Creating logical volumes

 1. enter lsdev -C -c disk to check disks available
 2. create volume group using: mkvg -y "vgname" hdiskn
 3. enter varyonvg vgname
 4. To create logical volume enter:mklv -y "lvname volgrp n
    e.g.mklv -y "testlv1" testvg 64 - will create a logical volume called
    testlv1 in volume group testvg of 64 logical partitions (to check the
    size of the physical partitions, run lsvg vgname)
 5. To create a mirrored logical volume enter:mklv -y "lvname -c n volgrp n
    disk1 disk2
    e.g.mklv -y "testlv2" -c 2 testvg 64 hdisk1 hdisk2 - will create a
    logical volume called testlv2 in volume group testvg with 2 copies of the
    64 logical partitions on disks hdisk1 and hdisk2
 6. create filesystem by entering crfs -v jfs -l lvname -m /mountdir -A yes
    This will dreate a filesystem the same size as the logical volume, create
    the mount directory and include the filesystem in /etc/filesystems so it
    will be automatically mounted when the system is rebooted.

Extending logical volumes

 1. enter extendlv lvname size - to extend the named logical volumes by the
    number of physical partitions named by the size parameter
 2. enter chfs -a size=+size /mountpoint - where size is in 512 byte blocks
    (can calculate this by (PP * 1000000)/512 ) and mountpoint is the
    physical mountpoint of the logical volume

Some useful LVM commands

  • lspv - list all disks on the system
  • lsvg - list all volume groups on the system
  • lsvg -l “vgname” - list all logical volumes in volume group
  • lsfs - list all filesystems in the system
  • mklvcopy -k lvname 2 pvname - will create a mirror copy of the named logical volume on named disk
  • lslv -m lvname - can be used to check logical volume mirrors
  • savevg - backup entire volume group, e.g.
    savevg -i volgrp /dev/rmt1
  • restvg - restore from savevg backup
  • mirrorvg - mirror an entire volume group, e.g.
    mirrorvg -s rootvg

Recent Changes