Hardware manual

Group Administration Advanced volume operations
10–16
Enabling and disabling a volume RAID preference
A PS Series group uses automatic performance load balancing (enabled by default) to identify the RAID level that
provides the best performance for a volume and store volume data on pool members with that RAID level, if such
members are available.
You can override automatic performance load
balancing by enabling a RAID level preference (RAID 10, RAID 50,
RAID 5, or RAID 6) on a volume.
If you enable a RAID preference, the group attempts to store volume data on
pool members with that RAID level.
The group still uses capacity-based load balancing on the volume.
If you disable a RAID preference on a volume, the group
resumes automatic performance load balancing.
Restriction: Thin clones
inherit the RAID preference, if any, of the template volume. You cannot set
a separate RAID preference for a thin clone.
Requirement: To
enable a volume RAID preference, make sure at least one member in the volume’s pool has the
preferred RAID level. If no pool member has the preferred RAID level, the group ignores the
RAID preference until a member exists with the preferred RAID level.
See Displaying storage pools on pag
e 7-3 to display the RAID levels of the pool members.
1. Click
Volumes, then expand Volumes, then select the volume, then click Modify settings, and then click
the
Advanced tab.
2. In the Modify volume settings – Advanced dialog box, under V
olume RAID preference, select the preferred
RAID level or select
Automatic to disable a RAID preference.
3. Click
OK.
Binding and unbinding a volume to a member
A PS Series group uses automatic performance load balancing (enabled by default) to identify the RAID level that
provides the best performance for a volume and store volume data on pool members with that RAID level, if such
members are available.
You can override automatic performance load balancing (or i
gnore any RAID preference for the volume) by
binding a volume to a specific pool member.
If you bind a volume to a pool member, the group stores the volume data on the member, instead of distributing
data across multiple pool members.
Y
ou can bind a volume only to a member that is in the same pool as the
volume. If you bind a volume to a member
and then delete that member from the pool or group, the group cancels the bind operation.
Restriction: Thin clones
inherit the member binding setting, if any, of the template volume. You
cannot have a separate member binding setting for a thin clone.
You cannot use the Group Manager GUI to bind a volume to a member
. Instead, you must use the following Group
Manager CLI command format:
volume select volume_name bind member_name