Sample LVM Procedures:

Filesystem Procedures

Procedure to create a filesystem using JFS:

See below the procedure for creating a logical volume and a filesystem using JFS:

Procedure to extend the size of filesystem using JFS:

“df” to see the filesystem, it’s current size, % utilization and the name of it’s logical volume

“lslv ” to show information about the logical volume including it’s volume group name.

“lsvg ” to show information about the volume group, including number of free pp’s and the pp size

If there are not enough free pp’s then see below for procedure to add a disk to a volume group.

“chfs -a size= +4194304 ” to grow the filesystem by 2 GB (4194304=2*1024*1024*1024/512)

NOTE: Growing the file system will automatically grow the logical volume

df” shows the file system’s current size is 2 GB more than before.

Troubleshooting extending the size of a filesystem using JFS:

Error Message: 0516-787 extendlv: Maximum allocation for logical volume is 512.

Maximum number of LPs for the logical volume has been exceeded – must increase the allocation

Calculate the number of LPs needed = LV Size in MB / LP size in MB

chlv -x

Procedure to remove a file system

Unmount the filesystem

Remove the logical volume “rmlv ”

Remove the filesystem information from /etc/filesystems

Procedure to reduce the size of a file system – shareold is 8mb and needs to be reduced to 4mb

Create the file system

crfs -v jfs -m /usr/sharenew -g rootvg -a size=8192

this makes a logical volume in the root volume group of 4MB that uses jfs

Mount the volume

mount /usr/sharenew

Move the files from the old file system (/usr/shareold)

cd /usr/shareold

tar cf –
(cd /usr/sharenew; tar xvf -)

cd

Unmount the file systems

umount /usr/sharenew

umount /usr/shareold

Remove the old file system and it’s logical volume

rmfs /usr/shareold

chfs -m /usr/shareold /usr/sharenew

Mount the new filesystem

mount /usr/shareold

Delete the temporary mount point

rmdir /usr/share

Logical Volume Procedures

Procedure to create a logical volume and filesystem in a volume group using JFS:

lsvg to determine the size of the PP

lslv in similar logical volumes to determine if mirroring is in effect

Calculate the number of PPs needed for the logical volume

bc

scale=2

/

quit

mklv -y “” <# of LPS> –> creates the logical volume

crfs -v jfs -d -m / -A yes –> makes the filesystem, creates the mountpoint and puts it in /etc/filesystems

mount / –> mounts the new fileystem

df / –> verifies the mount and the size of the new filesystem

Check the ownership and permissions of the new mount point

ls -ld

chown owner:group

chmod XXX

If mirroring is in effect, then mirror this logical volume to another disk (original and 1 mirror):

mklvcopy -s y 2

Check to see if all of the logical volumes in a volume group are mirrored

lsvg -l

Mirror a logical volume after the fact

mklvcopy -s y 2

Volume Group Procedures

Procedure to create a volume group:

lsdev -C -c disk -> lists available disks (and the hdisk#) on the server

mkvg -y “” hdisk# –> creates the volume group on the named hard disk

varyonvg –> activates the volume group

Procedure to add a disk to a volume group (extend the volume group)

extendvg

Verify the disk has been successfully added to the vg

lsvg -p

Procedure to mirror the rootvg:

lspv –> determine the hdisk#

extendvg rootvg hdisk –> add the hdisk to the volume group

lspv –> verify that the hdisk has been successfully added to the volume group

chvg -Q ‘n’ rootvg –> change the quorum so that the vg will stay active if one of the mirrors fail

mirrorvg -S -c 2 rootvg –> mirror all of the logical volumes in the volume group

lsvg -l rootvg –> verify successful mirroring (pps will appear “stale” until synchronization is complete).

bosboot -a –> update the boot image information

bootlist -m normal -o hdisk0 hdisk1 –> create a new bootlist

bootlist -m normal -o –> verify the bootlist is correct

Procedure to increase the number of LP’s available

Assume we receive an error that the maximum number of LP’s had been exceeded, and the maximum number of LP’s defined was 1100:

“lsvg ” to show the total PP’s available in the volume group =1250

“lsvg -l ” to show the total PP’s used in all logical volumes in that volume group (showed sys1log, the jfs log was using 2 PP’s)

“chlv -x 1248 ” to change the maximum number of LP’s from 1100 to 1248 (1250 PP’s in the volume group – 2 PP’s used by the jfs log = 1248 available)

Physical Disk Procedures

Procedure to find disks/vpaths that are unallocated

lsvpcfg

This will show disks/vpaths and the volume group they are allocated to

lspv
grep None

This will show pvs and whether they are asssociated with a volume group

Note: For vpaths, the hdisks will show as none, but they may be allocated to a vpath – you must grep each hdisk with the lsvpcfg

Procedure to make a new lun available to AIX

Allocate the new lun on the SAN

Run “cfgmgr”

Verify the new vpatch/hdisk by running “lsvpcfg”

There should be a new vpath and it should be available with no volume group – if not, rerun cfgmgr

Procedure to list the PVs in a volume group:

lsvg -p