HP (Hewlett-Packard) HP-UX 11i v3 Landscape Lighting User Manual


 
517Configuring Veritas Volume Manager
Guidelines for configuring storage
The hot-relocation feature is enabled by default. The associated daemon,
vxrelocd, is automatically started during system startup.
Refer to the following guidelines when using hot-relocation.
The hot-relocation feature is enabled by default. Although it is possible to
disable hot-relocation, it is advisable to leave it enabled. It will notify you of
the nature of the failure, attempt to relocate any affected subdisks that are
redundant, and initiate recovery procedures.
Although hot-relocation does not require you to designate disks as spares,
designate at least one disk as a spare within each disk group. This gives you
some control over which disks are used for relocation. If no spares exist,
Veritas Volume Manager uses any available free space within the disk group.
When free space is used for relocation purposes, it is possible to have
performance degradation after the relocation.
After hot-relocation occurs, designate one or more additional disks as spares
to augment the spare space. Some of the original spare space may be
occupied by relocated subdisks.
If a given disk group spans multiple controllers and has more than one spare
disk, set up the spare disks on different controllers (in case one of the
controllers fails).
For a mirrored volume, configure the disk group so that there is at least one
disk that does not already contain a mirror of the volume. This disk should
either be a spare disk with some available space or a regular disk with some
free space and the disk is not excluded from hot-relocation use.
For a mirrored and striped volume, configure the disk group so that at least
one disk does not already contain one of the mirrors of the volume or
another subdisk in the striped plex. This disk should either be a spare disk
with some available space or a regular disk with some free space and the
disk is not excluded from hot-relocation use.
For a RAID-5 volume, configure the disk group so that at least one disk does
not already contain the RAID-5 plex (or one of its log plexes) of the volume.
This disk should either be a spare disk with some available space or a
regular disk with some free space and the disk is not excluded from hot-
relocation use.
If a mirrored volume has a DRL log subdisk as part of its data plex, you
cannot relocate the data plex. Instead, place log subdisks in log plexes that
contain no data.
Hot-relocation does not guarantee to preserve the original performance
characteristics or data layout. Examine the locations of newly-relocated