Filter
Top Products
516 Configuring Veritas Volume Manager
Guidelines for configuring storage
■ If more than one plex of a mirrored volume is striped, configure the same
stripe-unit size for each striped plex.
■ Where possible, distribute the subdisks of a striped volume across drives
connected to different controllers and buses.
■ Avoid the use of controllers that do not support overlapped seeks. (Such
controllers are rare.)
The vxassist command automatically applies and enforces many of these
rules when it allocates space for striped plexes in a volume.
For more information, see “Striping (RAID-0)” on page 38.
RAID-5 guidelines
Refer to the following guidelines when using RAID-5.
In general, the guidelines for mirroring and striping together also apply to
RAID-5. The following guidelines should also be observed with RAID-5:
■ Only one RAID-5 plex can exist per RAID-5 volume (but there can be
multiple log plexes).
■ The RAID-5 plex must be derived from at least three subdisks on three or
more physical disks. If any log plexes exist, they must belong to disks other
than those used for the RAID-5 plex.
■ RAID-5 logs can be mirrored and striped.
■ If the volume length is not explicitly specified, it is set to the length of any
RAID-5 plex associated with the volume; otherwise, it is set to zero. If you
specify the volume length, it must be a multiple of the stripe-unit size of the
associated RAID-5 plex, if any.
■ If the log length is not explicitly specified, it is set to the length of the
smallest RAID-5 log plex that is associated, if any. If no RAID-5 log plexes
are associated, it is set to zero.
■ Sparse RAID-5 log plexes are not valid.
■ RAID-5 volumes are not supported for sharing in a cluster.
For more information, see “RAID-5 (striping with parity)” on page 45.
Hot-relocation guidelines
Hot-relocation automatically restores redundancy and access to mirrored and
RAID-5 volumes when a disk fails. This is done by relocating the affected
subdisks to disks designated as spares and/or free space in the same disk group.