IBM has given parts of the AIX LVM to Linux, so it would only stand to reason that there is a set of AIX-like commands for linux to use. This shows how to basically create a filesystem. A more comprehensive introduction to LVM is at:
HowtoForge
I have created 4 new partitions and got them available to linux for a test:
cd /dev
ls
brw-r----- 1 root disk 8, 32 Nov 3 10:52 sdc
brw-r----- 1 root disk 8, 48 Nov 3 10:52 sdd
brw-r----- 1 root disk 8, 64 Nov 3 10:52 sde
brw-r----- 1 root disk 8, 80 Nov 3 10:52 sdf
And the LVM command that I find are:
lvm
lvmchange
lvmdiskscan
lvmsadc
lvmsar
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pvchange
pvcreate
pvdisplay
pvmove
pvremove
pvresize
pvs
pvscan
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vgcfgbackup
vgcfgrestore
vgchange
vgck
vgconvert
vgcreate
vgdisplay
vgexport
vgextend
vgimport
vgmerge
vgmknodes
vgreduce
vgremove
vgrename
vgs
vgscan
vgsplit
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I start with pvcreate:
pvcreate /dev/sdc /dev/sdd /dev/sde /dev/sdf
Physical volume "/dev/sdc" successfully created
Physical volume "/dev/sdd" successfully created
Physical volume "/dev/sde" successfully created
Physical volume "/dev/sdf" successfully created
Next I display what I have done:
pvdisplay
--- Physical volume ---
PV Name /dev/sdb1
VG Name system
PV Size 15.00 GB / not usable 0
Allocatable yes
PE Size (KByte) 4096
Total PE 3839
Free PE 24
Allocated PE 3815
PV UUID Vydyz4-Njvf-6Wyk-Xl2s-UQM1-VcG4-Gbdk9a
--- NEW Physical volume ---
PV Name /dev/sdc
VG Name
PV Size 3.75 GB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID dYMnY2-V4By-N21v-s4Bh-nfMz-TKOp-xrmT2s
I already had one volume created (sdb1) and it clearly shows up a little different. The new
ones all say ‘NEW’ for one thing, and don’t yet show Allocatable, probably because they aren’t associated with a logical volume yet. First, they need a volume group, though:
vgcreate testvg /dev/sdc /dev/sdd /dev/sde /dev/sdf
Volume group "testvg" successfully created
And the display command shows what we did:
vgdisplay
--- Volume group ---
VG Name system
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 15.00 GB
PE Size 4.00 MB
Total PE 3839
Alloc PE / Size 3815 / 14.90 GB
Free PE / Size 24 / 96.00 MB
VG UUID F8PeFV-TIJj-YHqB-SpYv-Qxgn-UuwH-yE8eQH
Just like in AIX, the volume group can now be split into logical volumes:
lvcreate --name testlv1 --size 2G testvg
Logical volume "testlv1" created
lvcreate --name testlv2 --size 2G testvg
Logical volume "testlv2" created
lvdisplay
--- Logical volume ---
LV Name /dev/testvg/testlv1
VG Name testvg
LV UUID ixjAYJ-A8Uz-CUga-OCmo-HBvv-OaC0-wkR0pN
LV Write Access read/write
LV Status available
# open 0
LV Size 2.00 GB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
The maps flag is probably something close to AIX’s lsvg -l:
lvdisplay --maps
--- Logical volume ---
LV Name /dev/testvg/testlv1
VG Name testvg
LV UUID ixjAYJ-A8Uz-CUga-OCmo-HBvv-OaC0-wkR0pN
LV Write Access read/write
LV Status available
# open 0
LV Size 2.00 GB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1
--- Segments ---
Logical extent 0 to 511:
Type linear
Physical volume /dev/sdc
Physical extents 0 to 511
Even though we can make reference to volume group names (testvg) directly, logical
volumes seem to be named specifically as their device location. To extend and reduce
the size of the logical volume, we have to say:
lvextend -L 2.5G /dev/testvg/testlv2
Extending logical volume testlv2 to 2.50 GB
Logical volume testlv2 successfully resized
lvreduce -L 2G /dev/testvg/testlv2
WARNING: Reducing active logical volume to 2.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce testlv2? [y/n]: y
Reducing logical volume testlv2 to 2.00 GB
Logical volume testlv2 successfully resized
Next, lets build a filesystem:
mkfs.ext3 /dev/testvg/testlv1
mke2fs 1.38 (30-Jun-2005)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
262144 inodes, 524288 blocks
26214 blocks (5.00%) reserved for the super user
First data block=0
16 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
Finally, all we have to do is mount the filesystem and add a line to /etc/fstab for it:
mkdir /test
mount /dev/testvg/testlv1 /test
df -u
(add to /etc/fstab)
/dev/testvg/testlv1 /test ext3 rw,noatime 0 0
Another LVM Howto