The system has six SCSI hard disks, /dev/sda - /dev/sdf. /dev/sda is used for the Debian Etch system itself, while we will use /dev/sdb - /dev/sdf for LVM and RAID. /dev/sdb - /dev/sdf each have 80GB of disk space. In the beginning we will act as if each has only 25GB of disk space (thus using only 25GB on each of them), and in the course of the tutorial we will "replace" our 25GB hard disks with 80GB hard disks, thus demonstrating how you can replace small hard disks with bigger ones in LVM.
2 LVM Layout
Basically LVM looks like this:Scenario with details :
You have one or more physical volumes (/dev/sdb1 - /dev/sde1 in our example), and on these physical volumes you create one or more volume groups (e.g. fileserver), and in each volume group you can create one or more logical volumes. If you use multiple physical volumes, each logical volume can be bigger than one of the underlying physical volumes (but of course the sum of the logical volumes cannot exceed the total space offered by the physical volumes).
It is a good practice to not allocate the full space to logical volumes, but leave some space unused. That way you can enlarge one or more logical volumes later on if you feel the need for it.
In this example we will create a volume group called fileserver, and we will also create the logical volumes /dev/fileserver/share, /dev/fileserver/backup, and /dev/fileserver/media (which will use only half of the space offered by our physical volumes for now - that way we can switch to RAID1 later on (also described in this tutorial)).
3 Our First LVM Setup
Let's find out about our hard disks:fdisk -l
The output looks like this:server1:~# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdc doesn't contain a valid partition table
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdd doesn't contain a valid partition table
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sde doesn't contain a valid partition table
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdf doesn't contain a valid partition table
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdc doesn't contain a valid partition table
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdd doesn't contain a valid partition table
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sde doesn't contain a valid partition table
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdf doesn't contain a valid partition table
There are no partitions yet on /dev/sdb - /dev/sdf.
We will create the partitions /dev/sdb1, /dev/sdc1, /dev/sdd1, and /dev/sde1 and leave /dev/sdf untouched for now. We act as if our hard disks had only 25GB of space instead of 80GB for now, therefore we assign 25GB to /dev/sdb1, /dev/sdc1, /dev/sdd1, and /dev/sde1:
fdisk /dev/sdb
server1:~# fdisk /dev/sdb
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1): <--
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L
0 Empty 1e Hidden W95 FAT1 80 Old Minix be Solaris boot
1 FAT12 24 NEC DOS 81 Minix / old Lin bf Solaris
2 XENIX root 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
5 Extended 41 PPC PReP Boot 85 Linux extended c7 Syrinx
6 FAT16 42 SFS 86 NTFS volume set da Non-FS data
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM df BootIt
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e1 DOS access
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS e4 SpeedStor
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ee EFI GPT
10 OPUS 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f4 SpeedStor
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fd Linux raid auto
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fe LANstep
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid ff BBT
1c Hidden W95 FAT3 75 PC/IX
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1): <--
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L
0 Empty 1e Hidden W95 FAT1 80 Old Minix be Solaris boot
1 FAT12 24 NEC DOS 81 Minix / old Lin bf Solaris
2 XENIX root 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
5 Extended 41 PPC PReP Boot 85 Linux extended c7 Syrinx
6 FAT16 42 SFS 86 NTFS volume set da Non-FS data
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM df BootIt
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e1 DOS access
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS e4 SpeedStor
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ee EFI GPT
10 OPUS 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f4 SpeedStor
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fd Linux raid auto
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fe LANstep
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid ff BBT
1c Hidden W95 FAT3 75 PC/IX
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Now we do the same for the hard disks /dev/sdc - /dev/sde:
fdisk /dev/sdc
fdisk /dev/sdd
fdisk /dev/sde
fdisk /dev/sdd
fdisk /dev/sde
Then run
fdisk -l
again. The output should look like this:
server1:~# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sde1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdf doesn't contain a valid partition table
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sde1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdf doesn't contain a valid partition table
Now we prepare our new partitions for LVM:
pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
server1:~# pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdc1" successfully created
Physical volume "/dev/sdd1" successfully created
Physical volume "/dev/sde1" successfully created
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdc1" successfully created
Physical volume "/dev/sdd1" successfully created
Physical volume "/dev/sde1" successfully created
Let's revert this last action for training purposes:
pvremove /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
server1:~# pvremove /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Labels on physical volume "/dev/sdb1" successfully wiped
Labels on physical volume "/dev/sdc1" successfully wiped
Labels on physical volume "/dev/sdd1" successfully wiped
Labels on physical volume "/dev/sde1" successfully wiped
Labels on physical volume "/dev/sdb1" successfully wiped
Labels on physical volume "/dev/sdc1" successfully wiped
Labels on physical volume "/dev/sdd1" successfully wiped
Labels on physical volume "/dev/sde1" successfully wiped
Then run
pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
again:
server1:~# pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdc1" successfully created
Physical volume "/dev/sdd1" successfully created
Physical volume "/dev/sde1" successfully created
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdc1" successfully created
Physical volume "/dev/sdd1" successfully created
Physical volume "/dev/sde1" successfully created
Now run
pvdisplay
to learn about the current state of your physical volumes:
server1:~# pvdisplay
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID G8lu2L-Hij1-NVde-sOKc-OoVI-fadg-Jd1vyU
--- NEW Physical volume ---
PV Name /dev/sdc1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B
--- NEW Physical volume ---
PV Name /dev/sdd1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B
--- NEW Physical volume ---
PV Name /dev/sde1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID G8lu2L-Hij1-NVde-sOKc-OoVI-fadg-Jd1vyU
--- NEW Physical volume ---
PV Name /dev/sdc1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B
--- NEW Physical volume ---
PV Name /dev/sdd1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B
--- NEW Physical volume ---
PV Name /dev/sde1
VG Name
PV Size 23.29 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6
Now let's create our volume group fileserver and add /dev/sdb1 - /dev/sde1 to it:
vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
server1:~# vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Volume group "fileserver" successfully created
Volume group "fileserver" successfully created
Let's learn about our volume groups:
vgdisplay
server1:~# vgdisplay
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 0 / 0
Free PE / Size 23844 / 93.14 GB
VG UUID 3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 0 / 0
Free PE / Size 23844 / 93.14 GB
VG UUID 3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP
Another command to learn about our volume groups:
vgscan
server1:~# vgscan
Reading all physical volumes. This may take a while...
Found volume group "fileserver" using metadata type lvm2
Reading all physical volumes. This may take a while...
Found volume group "fileserver" using metadata type lvm2
For training purposes let's rename our volumegroup fileserver into data:
vgrename fileserver data
server1:~# vgrename fileserver data
Volume group "fileserver" successfully renamed to "data"
Volume group "fileserver" successfully renamed to "data"
Let's run vgdisplay and vgscan again to see if the volume group has been renamed:
vgdisplay
server1:~# vgdisplay
--- Volume group ---
VG Name data
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 0 / 0
Free PE / Size 23844 / 93.14 GB
VG UUID 3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP
--- Volume group ---
VG Name data
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 0 / 0
Free PE / Size 23844 / 93.14 GB
VG UUID 3Y1WVF-BLET-QkKs-Qnrs-SZxI-wrNO-dTqhFP
vgscan
server1:~# vgscan
Reading all physical volumes. This may take a while...
Found volume group "data" using metadata type lvm2
Reading all physical volumes. This may take a while...
Found volume group "data" using metadata type lvm2
Now let's delete our volume group data:
vgremove data
server1:~# vgremove data
Volume group "data" successfully removed
Volume group "data" successfully removed
vgdisplay
No output this time:
server1:~# vgdisplay
vgscan
server1:~# vgscan
Reading all physical volumes. This may take a while...
Reading all physical volumes. This may take a while...
Let's create our volume group fileserver again:
vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
server1:~# vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Volume group "fileserver" successfully created
Volume group "fileserver" successfully created
Next we create our logical volumes share (40GB), backup (5GB), and media (1GB) in the volume group fileserver. Together they use a little less than 50% of the available space (that way we can make use of RAID1 later on):
lvcreate --name share --size 40G fileserver
server1:~# lvcreate --name share --size 40G fileserver
Logical volume "share" created
Logical volume "share" created
lvcreate --name backup --size 5G fileserver
server1:~# lvcreate --name backup --size 5G fileserver
Logical volume "backup" created
Logical volume "backup" created
lvcreate --name media --size 1G fileserver
server1:~# lvcreate --name media --size 1G fileserver
Logical volume "media" created
Logical volume "media" created
Let's get an overview of our logical volumes:
lvdisplay
server1:~# lvdisplay
--- Logical volume ---
LV Name /dev/fileserver/share
VG Name fileserver
LV UUID 280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
LV Write Access read/write
LV Status available
# open 0
LV Size 40.00 GB
Current LE 10240
Segments 2
Allocation inherit
Read ahead sectors 0
Block device 253:0
--- Logical volume ---
LV Name /dev/fileserver/backup
VG Name fileserver
LV UUID zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
LV Write Access read/write
LV Status available
# open 0
LV Size 5.00 GB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Logical volume ---
LV Name /dev/fileserver/media
VG Name fileserver
LV UUID usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
LV Write Access read/write
LV Status available
# open 0
LV Size 1.00 GB
Current LE 256
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:2
--- Logical volume ---
LV Name /dev/fileserver/share
VG Name fileserver
LV UUID 280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
LV Write Access read/write
LV Status available
# open 0
LV Size 40.00 GB
Current LE 10240
Segments 2
Allocation inherit
Read ahead sectors 0
Block device 253:0
--- Logical volume ---
LV Name /dev/fileserver/backup
VG Name fileserver
LV UUID zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
LV Write Access read/write
LV Status available
# open 0
LV Size 5.00 GB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Logical volume ---
LV Name /dev/fileserver/media
VG Name fileserver
LV UUID usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
LV Write Access read/write
LV Status available
# open 0
LV Size 1.00 GB
Current LE 256
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:2
lvscan
server1:~# lvscan
ACTIVE '/dev/fileserver/share' [40.00 GB] inherit
ACTIVE '/dev/fileserver/backup' [5.00 GB] inherit
ACTIVE '/dev/fileserver/media' [1.00 GB] inherit
ACTIVE '/dev/fileserver/share' [40.00 GB] inherit
ACTIVE '/dev/fileserver/backup' [5.00 GB] inherit
ACTIVE '/dev/fileserver/media' [1.00 GB] inherit
For training purposes we rename our logical volume media into films:
lvrename fileserver media films
server1:~# lvrename fileserver media films
Renamed "media" to "films" in volume group "fileserver"
Renamed "media" to "films" in volume group "fileserver"
lvdisplay
server1:~# lvdisplay
--- Logical volume ---
LV Name /dev/fileserver/share
VG Name fileserver
LV UUID 280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
LV Write Access read/write
LV Status available
# open 0
LV Size 40.00 GB
Current LE 10240
Segments 2
Allocation inherit
Read ahead sectors 0
Block device 253:0
--- Logical volume ---
LV Name /dev/fileserver/backup
VG Name fileserver
LV UUID zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
LV Write Access read/write
LV Status available
# open 0
LV Size 5.00 GB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Logical volume ---
LV Name /dev/fileserver/films
VG Name fileserver
LV UUID usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
LV Write Access read/write
LV Status available
# open 0
LV Size 1.00 GB
Current LE 256
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:2
--- Logical volume ---
LV Name /dev/fileserver/share
VG Name fileserver
LV UUID 280Mup-H9aa-sn0S-AXH3-04cP-V6p9-lfoGgJ
LV Write Access read/write
LV Status available
# open 0
LV Size 40.00 GB
Current LE 10240
Segments 2
Allocation inherit
Read ahead sectors 0
Block device 253:0
--- Logical volume ---
LV Name /dev/fileserver/backup
VG Name fileserver
LV UUID zZeuKg-Dazh-aZMC-Aa99-KUSt-J6ET-KRe0cD
LV Write Access read/write
LV Status available
# open 0
LV Size 5.00 GB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Logical volume ---
LV Name /dev/fileserver/films
VG Name fileserver
LV UUID usfvrv-BC92-3pFH-2NW0-2N3e-6ERQ-4Sj7YS
LV Write Access read/write
LV Status available
# open 0
LV Size 1.00 GB
Current LE 256
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:2
lvscan
server1:~# lvscan
ACTIVE '/dev/fileserver/share' [40.00 GB] inherit
ACTIVE '/dev/fileserver/backup' [5.00 GB] inherit
ACTIVE '/dev/fileserver/films' [1.00 GB] inherit
ACTIVE '/dev/fileserver/share' [40.00 GB] inherit
ACTIVE '/dev/fileserver/backup' [5.00 GB] inherit
ACTIVE '/dev/fileserver/films' [1.00 GB] inherit
Next let's delete the logical volume films:
lvremove /dev/fileserver/films
server1:~# lvremove /dev/fileserver/films
Do you really want to remove active logical volume "films"? [y/n]: <-- y
Logical volume "films" successfully removed
Do you really want to remove active logical volume "films"? [y/n]: <-- y
Logical volume "films" successfully removed
We create the logical volume media again:
lvcreate --name media --size 1G fileserver
server1:~# lvcreate --name media --size 1G fileserver
Logical volume "media" created
Logical volume "media" created
Now let's enlarge media from 1GB to 1.5GB:
lvextend -L1.5G /dev/fileserver/media
server1:~# lvextend -L1.5G /dev/fileserver/media
Extending logical volume media to 1.50 GB
Logical volume media successfully resized
Extending logical volume media to 1.50 GB
Logical volume media successfully resized
Let's shrink it to 1GB again:
lvreduce -L1G /dev/fileserver/media
server1:~# lvreduce -L1G /dev/fileserver/media
WARNING: Reducing active logical volume to 1.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce media? [y/n]: <-- y
Reducing logical volume media to 1.00 GB
Logical volume media successfully resized
WARNING: Reducing active logical volume to 1.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce media? [y/n]: <-- y
Reducing logical volume media to 1.00 GB
Logical volume media successfully resized
Until now we have three logical volumes, but we don't have any filesystems in them, and without a filesystem we can't save anything in them. Therefore we create an ext3 filesystem in share, an xfs filesystem in backup, and a reiserfs filesystem in media:
mkfs.ext3 /dev/fileserver/share
server1:~# mkfs.ext3 /dev/fileserver/share
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
5242880 inodes, 10485760 blocks
524288 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
320 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
5242880 inodes, 10485760 blocks
524288 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
320 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
mkfs.xfs /dev/fileserver/backup
server1:~# mkfs.xfs /dev/fileserver/backup
meta-data=/dev/fileserver/backup isize=256 agcount=8, agsize=163840 blks
= sectsz=512 attr=0
data = bsize=4096 blocks=1310720, imaxpct=25
= sunit=0 swidth=0 blks, unwritten=1
naming =version 2 bsize=4096
log =internal log bsize=4096 blocks=2560, version=1
= sectsz=512 sunit=0 blks
realtime =none extsz=65536 blocks=0, rtextents=0
meta-data=/dev/fileserver/backup isize=256 agcount=8, agsize=163840 blks
= sectsz=512 attr=0
data = bsize=4096 blocks=1310720, imaxpct=25
= sunit=0 swidth=0 blks, unwritten=1
naming =version 2 bsize=4096
log =internal log bsize=4096 blocks=2560, version=1
= sectsz=512 sunit=0 blks
realtime =none extsz=65536 blocks=0, rtextents=0
mkfs.reiserfs /dev/fileserver/media
server1:~# mkfs.reiserfs /dev/fileserver/media
mkfs.reiserfs 3.6.19 (2003 www.namesys.com)
A pair of credits:
Alexander Lyamin keeps our hardware running, and was very generous to our
project in many little ways.
Chris Mason wrote the journaling code for V3, which was enormously more useful
to users than just waiting until we could create a wandering log filesystem as
Hans would have unwisely done without him.
Jeff Mahoney optimized the bitmap scanning code for V3, and performed the big
endian cleanups.
Guessing about desired format.. Kernel 2.6.17-2-486 is running.
Format 3.6 with standard journal
Count of blocks on the device: 262144
Number of blocks consumed by mkreiserfs formatting process: 8219
Blocksize: 4096
Hash function used to sort names: "r5"
Journal Size 8193 blocks (first block 18)
Journal Max transaction length 1024
inode generation number: 0
UUID: 2bebf750-6e05-47b2-99b6-916fa7ea5398
ATTENTION: YOU SHOULD REBOOT AFTER FDISK!
ALL DATA WILL BE LOST ON '/dev/fileserver/media'!
Continue (y/n):y
Initializing journal - 0%....20%....40%....60%....80%....100%
Syncing..ok
Tell your friends to use a kernel based on 2.4.18 or later, and especially not a
kernel based on 2.4.9, when you use reiserFS. Have fun.
ReiserFS is successfully created on /dev/fileserver/media.
mkfs.reiserfs 3.6.19 (2003 www.namesys.com)
A pair of credits:
Alexander Lyamin keeps our hardware running, and was very generous to our
project in many little ways.
Chris Mason wrote the journaling code for V3, which was enormously more useful
to users than just waiting until we could create a wandering log filesystem as
Hans would have unwisely done without him.
Jeff Mahoney optimized the bitmap scanning code for V3, and performed the big
endian cleanups.
Guessing about desired format.. Kernel 2.6.17-2-486 is running.
Format 3.6 with standard journal
Count of blocks on the device: 262144
Number of blocks consumed by mkreiserfs formatting process: 8219
Blocksize: 4096
Hash function used to sort names: "r5"
Journal Size 8193 blocks (first block 18)
Journal Max transaction length 1024
inode generation number: 0
UUID: 2bebf750-6e05-47b2-99b6-916fa7ea5398
ATTENTION: YOU SHOULD REBOOT AFTER FDISK!
ALL DATA WILL BE LOST ON '/dev/fileserver/media'!
Continue (y/n):y
Initializing journal - 0%....20%....40%....60%....80%....100%
Syncing..ok
Tell your friends to use a kernel based on 2.4.18 or later, and especially not a
kernel based on 2.4.9, when you use reiserFS. Have fun.
ReiserFS is successfully created on /dev/fileserver/media.
Now we are ready to mount our logical volumes. I want to mount share in /var/share, backup in /var/backup, and media in /var/media, therefore we must create these directories first:
mkdir /var/media /var/backup /var/share
Now we can mount our logical volumes:
mount /dev/fileserver/share /var/share
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media
Now run
df -h
You should see your logical volumes in the output:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Congratulations, you've just set up your first LVM system! You can now write to and read from /var/share, /var/backup, and /var/media as usual.
We have mounted our logical volumes manually, but of course we'd like to have them mounted automatically when the system boots. Therefore we modify /etc/fstab:
mv /etc/fstab /etc/fstab_orig
cat /dev/null > /etc/fstab
cat /dev/null > /etc/fstab
vi /etc/fstab
Put the following into it:
# /etc/fstab: static file system information. # # proc /proc proc defaults 0 0 /dev/sda2 / ext3 defaults,errors=remount-ro 0 1 /dev/sda1 /boot ext3 defaults 0 2 /dev/hdc /media/cdrom0 udf,iso9660 user,noauto 0 0 /dev/fd0 /media/floppy0 auto rw,user,noauto 0 0 /dev/fileserver/share /var/share ext3 rw,noatime 0 0 /dev/fileserver/backup /var/backup xfs rw,noatime 0 0 /dev/fileserver/media /var/media reiserfs rw,noatime 0 0 |
If you compare it to our backup of the original file, /etc/fstab_orig, you will notice that we added the lines:
/dev/fileserver/share /var/share ext3 rw,noatime 0 0
/dev/fileserver/backup /var/backup xfs rw,noatime 0 0
/dev/fileserver/media /var/media reiserfs rw,noatime 0 0
/dev/fileserver/backup /var/backup xfs rw,noatime 0 0
/dev/fileserver/media /var/media reiserfs rw,noatime 0 0
Now we reboot the system:
shutdown -r now
After the system has come up again, run
df -h
again. It should still show our logical volumes in the output:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
In this chapter we will learn how to resize our logical volume share which has an ext3 filesystem. (I will show how to resize logical volumes with xfs and reiserfs filesystems further down this tutorial.)
First we must unmount it:
umount /var/share
share should not be listed anymore in the
df -h
output:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Now let's enlarge share from 40GB to 50GB:
lvextend -L50G /dev/fileserver/share
server1:~# lvextend -L50G /dev/fileserver/share
Extending logical volume share to 50.00 GB
Logical volume share successfully resized
Extending logical volume share to 50.00 GB
Logical volume share successfully resized
Until now we have enlarged only share, but not the ext3 filesystem on share. This is what we do now:
e2fsck -f /dev/fileserver/share
server1:~# e2fsck -f /dev/fileserver/share
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/5242880 files (9.1% non-contiguous), 209588/10485760 blocks
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/5242880 files (9.1% non-contiguous), 209588/10485760 blocks
Make a note of the total amount of blocks (10485760) because we need it when we shrink share later on.
resize2fs /dev/fileserver/share
server1:~# resize2fs /dev/fileserver/share
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 13107200 (4k) blocks.
The filesystem on /dev/fileserver/share is now 13107200 blocks long.
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 13107200 (4k) blocks.
The filesystem on /dev/fileserver/share is now 13107200 blocks long.
Let's mount share:
mount /dev/fileserver/share /var/share
and in the
df -h
output share should now have 50GB instead of 40:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
/dev/mapper/fileserver-share
50G 180M 47G 1% /var/share
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
/dev/mapper/fileserver-share
50G 180M 47G 1% /var/share
Shrinking a logical volume is the other way round: first we must shrink the filesystem before we reduce the logical volume's size. Let's shrink share to 40GB again:
umount /var/share
df -h
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
e2fsck -f /dev/fileserver/share
server1:~# e2fsck -f /dev/fileserver/share
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/6553600 files (9.1% non-contiguous), 251733/13107200 blocks
e2fsck 1.40-WIP (14-Nov-2006)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/fileserver/share: 11/6553600 files (9.1% non-contiguous), 251733/13107200 blocks
When resizing an ext3 filesystem to a certain size (instead of all available space), resize2fs takes the number of blocks as argument (you can as well specify the new size in MB, etc. See
man resize2fs
for more details). From our previous operation we know the 40GB equals 10485760 blocks so we run
resize2fs /dev/fileserver/share 10485760
server1:~# resize2fs /dev/fileserver/share 10485760
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 10485760 (4k) blocks.
The filesystem on /dev/fileserver/share is now 10485760 blocks long.
resize2fs 1.40-WIP (14-Nov-2006)
Resizing the filesystem on /dev/fileserver/share to 10485760 (4k) blocks.
The filesystem on /dev/fileserver/share is now 10485760 blocks long.
We've shrinked the filesystem, now we must shrink the logical volume, too:
lvreduce -L40G /dev/fileserver/share
server1:~# lvreduce -L40G /dev/fileserver/share
WARNING: Reducing active logical volume to 40.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce share? [y/n]: <-- y
Reducing logical volume share to 40.00 GB
Logical volume share successfully resized
WARNING: Reducing active logical volume to 40.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce share? [y/n]: <-- y
Reducing logical volume share to 40.00 GB
Logical volume share successfully resized
We can ignore the warning that data might be destroyed because we have shrinked the filesystem before.
Let's mount share again:
mount /dev/fileserver/share /var/share
The output of
df -h
should now look like this:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 88K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
We haven't used /dev/sdf until now. We will now create the partition /dev/sdf1 (25GB) and add that to our fileserver volume group.
fdisk /dev/sdf
server1:~# fdisk /dev/sdf
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-10443, default 10443): <-- +25000M
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Let's prepare /dev/sdf1 for LVM:
pvcreate /dev/sdf1
server1:~# pvcreate /dev/sdf1
Physical volume "/dev/sdf1" successfully created
Physical volume "/dev/sdf1" successfully created
Add /dev/sdf1 to our fileserver volume group:
vgextend fileserver /dev/sdf1
Run
vgdisplay
VG Size should now be bigger than before:
server1:~# vgdisplay
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 5
Metadata Sequence No 12
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 5
Act PV 5
VG Size 116.43 GB
PE Size 4.00 MB
Total PE 29805
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 18029 / 70.43 GB
VG UUID iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 5
Metadata Sequence No 12
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 5
Act PV 5
VG Size 116.43 GB
PE Size 4.00 MB
Total PE 29805
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 18029 / 70.43 GB
VG UUID iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO
That's it. /dev/sdf1 has been added to the fileserver volume group.
Now let's remove /dev/sdb1. Before we do this, we must copy all data on it to /dev/sdf1:
pvmove /dev/sdb1 /dev/sdf1
This can take some minutes:
server1:~# pvmove /dev/sdb1 /dev/sdf1
/dev/sdb1: Moved: 1.9%
/dev/sdb1: Moved: 3.8%
/dev/sdb1: Moved: 5.8%
/dev/sdb1: Moved: 7.8%
/dev/sdb1: Moved: 9.7%
/dev/sdb1: Moved: 11.6%
/dev/sdb1: Moved: 13.6%
/dev/sdb1: Moved: 15.6%
/dev/sdb1: Moved: 17.5%
/dev/sdb1: Moved: 19.4%
/dev/sdb1: Moved: 21.4%
[...]
/dev/sdb1: Moved: 85.7%
/dev/sdb1: Moved: 87.7%
/dev/sdb1: Moved: 89.7%
/dev/sdb1: Moved: 91.7%
/dev/sdb1: Moved: 93.6%
/dev/sdb1: Moved: 95.5%
/dev/sdb1: Moved: 97.5%
/dev/sdb1: Moved: 99.4%
/dev/sdb1: Moved: 100.0%
/dev/sdb1: Moved: 1.9%
/dev/sdb1: Moved: 3.8%
/dev/sdb1: Moved: 5.8%
/dev/sdb1: Moved: 7.8%
/dev/sdb1: Moved: 9.7%
/dev/sdb1: Moved: 11.6%
/dev/sdb1: Moved: 13.6%
/dev/sdb1: Moved: 15.6%
/dev/sdb1: Moved: 17.5%
/dev/sdb1: Moved: 19.4%
/dev/sdb1: Moved: 21.4%
[...]
/dev/sdb1: Moved: 85.7%
/dev/sdb1: Moved: 87.7%
/dev/sdb1: Moved: 89.7%
/dev/sdb1: Moved: 91.7%
/dev/sdb1: Moved: 93.6%
/dev/sdb1: Moved: 95.5%
/dev/sdb1: Moved: 97.5%
/dev/sdb1: Moved: 99.4%
/dev/sdb1: Moved: 100.0%
Next we remove /dev/sdb1 from the fileserver volume group:
vgreduce fileserver /dev/sdb1
server1:~# vgreduce fileserver /dev/sdb1
Removed "/dev/sdb1" from volume group "fileserver"
Removed "/dev/sdb1" from volume group "fileserver"
vgdisplay
server1:~# vgdisplay
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 16
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 12068 / 47.14 GB
VG UUID iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 16
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 12068 / 47.14 GB
VG UUID iWr1Vk-7h7J-hLRL-SHbx-3p87-Rq47-L1GyEO
Then we run
pvremove /dev/sdb1
/dev/sdb1 shouldn't be listed as a physical volume anymore:
pvdisplay
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/sdc1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 1682
Allocated PE 4279
PV UUID 40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 4681
Allocated PE 1280
PV UUID 4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B
--- Physical volume ---
PV Name /dev/sde1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5705
Allocated PE 256
PV UUID 3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6
--- Physical volume ---
PV Name /dev/sdf1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID 1xgo2I-SBjj-0MAz-lmDu-OLZ1-3NdO-mLkS20
--- Physical volume ---
PV Name /dev/sdc1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 1682
Allocated PE 4279
PV UUID 40GJyh-IbsI-pzhn-TDRq-PQ3l-3ut0-AVSE4B
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 4681
Allocated PE 1280
PV UUID 4mU63D-4s26-uL00-r0pO-Q0hP-mvQR-2YJN5B
--- Physical volume ---
PV Name /dev/sde1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5705
Allocated PE 256
PV UUID 3upcZc-4eS2-h4r4-iBKK-gZJv-AYt3-EKdRK6
--- Physical volume ---
PV Name /dev/sdf1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID 1xgo2I-SBjj-0MAz-lmDu-OLZ1-3NdO-mLkS20
You could now remove /dev/sdb from the system (if this was a real system and not a virtual machine).
In this chapter we will undo all changes from the previous chapters to return to the system's original state. This is just for training purposes so that you learn how to undo an LVM setup.
First we must unmount our logical volumes:
umount /var/share
umount /var/backup
umount /var/media
umount /var/backup
umount /var/media
df -h
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 665M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
Then we delete each of them:
lvremove /dev/fileserver/share
server1:~# lvremove /dev/fileserver/share
Do you really want to remove active logical volume "share"? [y/n]: <-- y
Logical volume "share" successfully removed
Do you really want to remove active logical volume "share"? [y/n]: <-- y
Logical volume "share" successfully removed
lvremove /dev/fileserver/backup
server1:~# lvremove /dev/fileserver/backup
Do you really want to remove active logical volume "backup"? [y/n]: <-- y
Logical volume "backup" successfully removed
Do you really want to remove active logical volume "backup"? [y/n]: <-- y
Logical volume "backup" successfully removed
lvremove /dev/fileserver/media
server1:~# lvremove /dev/fileserver/media
Do you really want to remove active logical volume "media"? [y/n]: <-- y
Logical volume "media" successfully removed
Do you really want to remove active logical volume "media"? [y/n]: <-- y
Logical volume "media" successfully removed
Next we remove the volume group fileserver:
vgremove fileserver
server1:~# vgremove fileserver
Volume group "fileserver" successfully removed
Volume group "fileserver" successfully removed
Finally we do this:
pvremove /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1
server1:~# pvremove /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1
Labels on physical volume "/dev/sdc1" successfully wiped
Labels on physical volume "/dev/sdd1" successfully wiped
Labels on physical volume "/dev/sde1" successfully wiped
Labels on physical volume "/dev/sdf1" successfully wiped
Labels on physical volume "/dev/sdc1" successfully wiped
Labels on physical volume "/dev/sdd1" successfully wiped
Labels on physical volume "/dev/sde1" successfully wiped
Labels on physical volume "/dev/sdf1" successfully wiped
vgdisplay
server1:~# vgdisplay
No volume groups found
No volume groups found
pvdisplay
should display nothing at all:
server1:~# pvdisplay
Now we must undo our changes in /etc/fstab to avoid that the system tries to mount non-existing devices. Fortunately we have made a backup of the original file that we can copy back now:
mv /etc/fstab_orig /etc/fstab
Reboot the system:
shutdown -r now
Afterwards the output of
df -h
should look like this:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
Now the system is like it was in the beginning (except that the partitions /dev/sdb1 - /dev/sdf1 still exist - you could delete them with fdisk but we don't do this now - as well as the directories /var/share, /var/backup, and /var/media which we also don't delete).
7 LVM On RAID1
In this chapter we will set up LVM again and move it to a RAID1 array to guarantee for high-availability. In the end this should look like this:
This means we will make the RAID array /dev/md0 from the partitions /dev/sdb1 + /dev/sdc1, and the RAID array /dev/md1 from the partitions /dev/sdd1 + /dev/sde1. /dev/md0 and /dev/md1 will then be the physical volumes for LVM.
Before we come to that, we set up LVM as before:
pvcreate /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
lvcreate --name share --size 40G fileserver
lvcreate --name backup --size 5G fileserver
lvcreate --name media --size 1G fileserver
vgcreate fileserver /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
lvcreate --name share --size 40G fileserver
lvcreate --name backup --size 5G fileserver
lvcreate --name media --size 1G fileserver
mkfs.ext3 /dev/fileserver/share
mkfs.xfs /dev/fileserver/backup
mkfs.reiserfs /dev/fileserver/media
mkfs.xfs /dev/fileserver/backup
mkfs.reiserfs /dev/fileserver/media
Then we mount our logical volumes:
mount /dev/fileserver/share /var/share
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media
mount /dev/fileserver/backup /var/backup
mount /dev/fileserver/media /var/media
The output of
df -h
should now look like this:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.0G 33M 992M 4% /var/media
Now we must move the contents of /dev/sdc1 and /dev/sde1 (/dev/sdc1 is the second partition of our future /dev/md0, /dev/sde1 the second partition of our future /dev/md1) to the remaining partitions, because we will afterwards remove them from LVM and format them with the type fd (Linux RAID autodetect) and move them to /dev/md0 resp. /dev/md1.
modprobe dm-mirror
pvmove /dev/sdc1
pvmove /dev/sdc1
vgreduce fileserver /dev/sdc1
pvremove /dev/sdc1
pvremove /dev/sdc1
pvdisplay
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 4681
Allocated PE 1280
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
--- Physical volume ---
PV Name /dev/sde1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 1426
Allocated PE 4535
PV UUID 4vL1e0-sr2M-awGd-qDJm-ZrC9-wuxW-2lEqp2
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 4681
Allocated PE 1280
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
--- Physical volume ---
PV Name /dev/sde1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 1426
Allocated PE 4535
PV UUID 4vL1e0-sr2M-awGd-qDJm-ZrC9-wuxW-2lEqp2
pvmove /dev/sde1
vgreduce fileserver /dev/sde1
pvremove /dev/sde1
pvremove /dev/sde1
pvdisplay
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
Now we format /dev/sdc1 with the type fd (Linux RAID autodetect):
fdisk /dev/sdc
server1:~# fdisk /dev/sdc
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L
0 Empty 1e Hidden W95 FAT1 80 Old Minix be Solaris boot
1 FAT12 24 NEC DOS 81 Minix / old Lin bf Solaris
2 XENIX root 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
5 Extended 41 PPC PReP Boot 85 Linux extended c7 Syrinx
6 FAT16 42 SFS 86 NTFS volume set da Non-FS data
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM df BootIt
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e1 DOS access
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS e4 SpeedStor
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ee EFI GPT
10 OPUS 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f4 SpeedStor
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fd Linux raid auto
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fe LANstep
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid ff BBT
1c Hidden W95 FAT3 75 PC/IX
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
The number of cylinders for this disk is set to 10443.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- L
0 Empty 1e Hidden W95 FAT1 80 Old Minix be Solaris boot
1 FAT12 24 NEC DOS 81 Minix / old Lin bf Solaris
2 XENIX root 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
5 Extended 41 PPC PReP Boot 85 Linux extended c7 Syrinx
6 FAT16 42 SFS 86 NTFS volume set da Non-FS data
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM df BootIt
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e1 DOS access
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS e4 SpeedStor
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ee EFI GPT
10 OPUS 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f4 SpeedStor
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fd Linux raid auto
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fe LANstep
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid ff BBT
1c Hidden W95 FAT3 75 PC/IX
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Now do the same with /dev/sde1:
fdisk /dev/sde
The output of
fdisk -l
should now look like this:
server1:~# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 3040 24418768+ fd Linux raid autodetect
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sde1 1 3040 24418768+ fd Linux raid autodetect
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdf1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 18 144553+ 83 Linux
/dev/sda2 19 2450 19535040 83 Linux
/dev/sda4 2451 2610 1285200 82 Linux swap / Solaris
Disk /dev/sdb: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sdc: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 3040 24418768+ fd Linux raid autodetect
Disk /dev/sdd: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 3040 24418768+ 8e Linux LVM
Disk /dev/sde: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sde1 1 3040 24418768+ fd Linux raid autodetect
Disk /dev/sdf: 85.8 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdf1 1 3040 24418768+ 8e Linux LVM
Next we add /dev/sdc1 to /dev/md0 and /dev/sde1 to /dev/md1. Because the second nodes (/dev/sdb1 and /dev/sdd1) are not ready yet, we must specify missing in the following commands:
mdadm --create /dev/md0 --auto=yes -l 1 -n 2 /dev/sdc1 missing
server1:~# mdadm --create /dev/md0 --auto=yes -l 1 -n 2 /dev/sdc1 missing
mdadm: array /dev/md0 started.
mdadm: array /dev/md0 started.
mdadm --create /dev/md1 --auto=yes -l 1 -n 2 /dev/sde1 missing
server1:~# mdadm --create /dev/md1 --auto=yes -l 1 -n 2 /dev/sde1 missing
mdadm: array /dev/md1 started.
mdadm: array /dev/md1 started.
Afterwards we prepare /dev/md0 and /dev/md1 for LVM:
pvcreate /dev/md0 /dev/md1
server1:~# pvcreate /dev/md0 /dev/md1
Physical volume "/dev/md0" successfully created
Physical volume "/dev/md1" successfully created
Physical volume "/dev/md0" successfully created
Physical volume "/dev/md1" successfully created
and extend our fileserver volume group:
vgextend fileserver /dev/md0 /dev/md1
server1:~# vgextend fileserver /dev/md0 /dev/md1
Volume group "fileserver" successfully extended
Volume group "fileserver" successfully extended
The outputs of
Pvdisplay and vgdisplay should look like this:
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
--- Physical volume ---
PV Name /dev/md0
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5961
Allocated PE 0
PV UUID 7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P
--- Physical volume ---
PV Name /dev/md1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5961
Allocated PE 0
PV UUID pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW
--- Physical volume ---
PV Name /dev/sdb1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID USDJyG-VDM2-r406-OjQo-h3eb-c9Mp-4nvnvu
--- Physical volume ---
PV Name /dev/sdd1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID qdEB5d-389d-O5UA-Kbwv-mn1y-74FY-4zublN
--- Physical volume ---
PV Name /dev/md0
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5961
Allocated PE 0
PV UUID 7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P
--- Physical volume ---
PV Name /dev/md1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 5961
Allocated PE 0
PV UUID pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW
server1:~# vgdisplay
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 14
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 12068 / 47.14 GB
VG UUID dQDEHT-kNHf-UjRm-rmJ3-OUYx-9G1t-aVskI1
--- Volume group ---
VG Name fileserver
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 14
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 4
Act PV 4
VG Size 93.14 GB
PE Size 4.00 MB
Total PE 23844
Alloc PE / Size 11776 / 46.00 GB
Free PE / Size 12068 / 47.14 GB
VG UUID dQDEHT-kNHf-UjRm-rmJ3-OUYx-9G1t-aVskI1
Now we move the contents of /dev/sdb1 to /dev/md0 and the contents of /dev/sdd1 to /dev/md1, then we remove /dev/sdb1 and /dev/sdd1 from LVM:
pvmove /dev/sdb1 /dev/md0
pvmove /dev/sdd1 /dev/md1
vgreduce fileserver /dev/sdb1 /dev/sdd1
pvremove /dev/sdb1 /dev/sdd1
pvremove /dev/sdb1 /dev/sdd1
Now only /dev/md0 and /dev/md1 should be left as physical volumes:
pvdisplay
server1:~# pvdisplay
--- Physical volume ---
PV Name /dev/md0
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID 7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P
--- Physical volume ---
PV Name /dev/md1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW
--- Physical volume ---
PV Name /dev/md0
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes (but full)
PE Size (KByte) 4096
Total PE 5961
Free PE 0
Allocated PE 5961
PV UUID 7JHUXF-1R2p-OjbJ-X1OT-uaeg-gWRx-H6zx3P
--- Physical volume ---
PV Name /dev/md1
VG Name fileserver
PV Size 23.29 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 5961
Free PE 146
Allocated PE 5815
PV UUID pwQ5AJ-RwVK-EebA-0Z13-d27d-2IdP-HqT5RW
Now we format /dev/sdb1 with fd (Linux RAID autodetect):
fdisk /dev/sdb
server1:~# fdisk /dev/sdb
The number of cylinders for this disk is set to 32635.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
The number of cylinders for this disk is set to 32635.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): <-- m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Do the same with /dev/sdd1:
fdisk /dev/sdd
Next add /dev/sdb1 to /dev/md0 and /dev/sdd1 to /dev/md1:
mdadm --manage /dev/md0 --add /dev/sdb1
server1:~# mdadm --manage /dev/md0 --add /dev/sdb1
mdadm: added /dev/sdb1
mdadm: added /dev/sdb1
mdadm --manage /dev/md1 --add /dev/sdd1
server1:~# mdadm --manage /dev/md1 --add /dev/sdd1
mdadm: added /dev/sdd1
mdadm: added /dev/sdd1
Now the two RAID arrays will be synchronized. This will take some time, you can check with
cat /proc/mdstat
when the process is finished. The output looks like this for an unfinished process:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[2] sde1[0]
24418688 blocks [2/1] [U_]
[=>...................] recovery = 6.4% (1586560/24418688) finish=1.9min speed=198320K/sec
md0 : active raid1 sdb1[2] sdc1[0]
24418688 blocks [2/1] [U_]
[==>..................] recovery = 10.5% (2587264/24418688) finish=2.8min speed=129363K/sec
unused devices:
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[2] sde1[0]
24418688 blocks [2/1] [U_]
[=>...................] recovery = 6.4% (1586560/24418688) finish=1.9min speed=198320K/sec
md0 : active raid1 sdb1[2] sdc1[0]
24418688 blocks [2/1] [U_]
[==>..................] recovery = 10.5% (2587264/24418688) finish=2.8min speed=129363K/sec
unused devices:
and like this when the process is finished:
server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[1] sde1[0]
24418688 blocks [2/2] [UU]
md0 : active raid1 sdb1[1] sdc1[0]
24418688 blocks [2/2] [UU]
unused devices:
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md1 : active raid1 sdd1[1] sde1[0]
24418688 blocks [2/2] [UU]
md0 : active raid1 sdb1[1] sdc1[0]
24418688 blocks [2/2] [UU]
unused devices:
If you have a look at PV Size in the output of
pvdisplay
you will see that 2 * 23.29GB = 46.58GB are available, however only 40GB (share) + 5GB (backup) + 1GB (media) = 46GB are used which means we could extend one of our logical devices with about 0.5GB. I've already shown how to extend an ext3 logical volume (share), so we will resize media now which uses reiserfs. reiserfs filesystems can be resized without unmounting:
lvextend -L1.5G /dev/fileserver/media
server1:~# lvextend -L1.5G /dev/fileserver/media
Extending logical volume media to 1.50 GB
Logical volume media successfully resized
Extending logical volume media to 1.50 GB
Logical volume media successfully resized
resize_reiserfs /dev/fileserver/media
server1:~# resize_reiserfs /dev/fileserver/media
resize_reiserfs 3.6.19 (2003 www.namesys.com)
resize_reiserfs 3.6.19 (2003 www.namesys.com)
resize_reiserfs: On-line resizing finished successfully.
The output of
df -h
looks like this:
server1:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.5G 33M 1.5G 3% /var/media
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 19G 666M 17G 4% /
tmpfs 78M 0 78M 0% /lib/init/rw
udev 10M 92K 10M 1% /dev
tmpfs 78M 0 78M 0% /dev/shm
/dev/sda1 137M 17M 114M 13% /boot
/dev/mapper/fileserver-share
40G 177M 38G 1% /var/share
/dev/mapper/fileserver-backup
5.0G 144K 5.0G 1% /var/backup
/dev/mapper/fileserver-media
1.5G 33M 1.5G 3% /var/media
If we want our logical volumes to be mounted automatically at boot time, we must modify /etc/fstab again (like in chapter 3):
mv /etc/fstab /etc/fstab_orig
cat /dev/null > /etc/fstab
cat /dev/null > /etc/fstab
vi /etc/fstab
