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:
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 |
pvchange pvcreate pvdisplay pvmove pvremove pvresize pvs pvscan |
vgcfgbackup vgcfgrestore vgchange vgck vgconvert vgcreate vgdisplay vgexport vgextend vgimport vgmerge vgmknodes vgreduce vgremove vgrename vgs vgscan vgsplit |
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