Preparing for LVM System Recovery
To ensure that the system data and configuration are recoverable in the event of a system failure,
follow these steps:
1.
Load any patches for LVM.
2.
Use Ignite-UX to create a recovery image of your root volume group. Although Ignite-UX is not
intended to be used to back up all system data, you can use it with other data recovery
applications to create a method of total system recovery.
3.
Perform regular backups of the other important data on your system.
Without a valid backup, you risk losing some or all of your data.
4.
Regularly print out your system configuration.
The configuration details stored on the system might not be accessible during a recovery. A
printed copy is an invaluable reference. HP recommends printing the configuration details
once a week and every time a change is made. Some of the commands create large amounts
of output. An alternative to printing them is to output the information to a file and then storing
the file on tape which enables quick recovery of the information when needed. You can include
this configuration file with the backup in step 3.
The easiest way to save the configuration is to set up a
cron
job to run regularly, so that the
system backs it up automatically.
Use the following commands to get a useful output:
/usr/sbin/ioscan -fk
/usr/sbin/vgdisplay -v
/usr/sbin/lvlnboot -v
/usr/sbin/lvdisplay -v /dev/vgXX/lvYY
(for every logical volume)
/usr/sbin/pvdisplay -v /dev/dsk/c#t#d0
(for every LVM disk)
lp /etc/fstab
As an alternative, you can write an intelligent script that detects any changes in the
configuration and only print out those changes. An example script is included at the end of
this section.
5.
Back up the LVM configuration after every configuration change.
The
vgcfgbackup
command copies the LVM headers from the system area of the disk to a
disk file, which resides in the
/etc/lvmconf
directory. This default directory can be changed
for volume group Version 2.x by configuring a new path in the
LVMP_CONF_PATH_NON_BOOT
variable in the
/etc/lvmrc
file (see vgcfgbackup(1M) for more information). After this
information is stored in a disk file, it can be backed up to tape during file system backups.
The information in this file enables you to replace the LVM headers on the disk in the event of
the disk being replaced or your LVM configuration becoming corrupted.
It is important that these configuration backups are taken whenever you make a change to
any part of the LVM configuration. By default all the commands perform a backup so a manual
vgcfgbackup
after each command is not required.
Do this task on a regular basis, whether you have made changes or not. Enter the following
command:
# /usr/sbin/vgcfgbackup /dev/vgXX (for every volume group)
Planning for Recovery
35
