Dell EqualLogic PS6210XS EqualLogic Group Manager Administrator s Guide PS Ser - Page 131

Enable and Disable a Volume RAID Preference, Prerequisites, Procedure

Page 131 highlights

RAID Policy RAID 50 RAID 5 Spare Disks RAID Set Relationship 2 (6+1 ,6+,1, 6+1, 6+1, 6+1, 6+1) (3+1) 2 (12+1, 12+1, 12+1) (6+1) Best Practices For selected configurations Not for business-critical data Table 31. 84-Drive Configuration shows the RAID set relationship for each RAID type in a 84-drive configuration. Table 31. 84-Drive Configuration RAID Policy Spare Disks RAID Set Relationship RAID 6 2 (12+2) (12+2) (12+2) (12+2) (12+2) (10+2) RAID 6 Accelerated 1 HHD 1 SSD (12+2 HDD) (12+2 HDD) (12+2 HDD) (12+2 HDD) (10+2 HDD) (12+2 SSD) Best Practices Yes N/A RAID 10 2 RAID 50 2 RAID 5 2 (7+7) (7+7) (7+7) (7+7) (7+7) (6+6) (12+2) (12+2) (12+2) (12+2) (12+2) (10+2) (12+2) (12+2) (12+2) (12+2) (12+2) (10+2) Yes Not for business-critical data Not for business-critical data Enable and Disable 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. Prerequisites The following prerequisites and considerations apply: • RAID 5 does not offer optimal data protection for business-critical data due to the higher risks of encountering a second drive failure during a rebuild, and is therefore not recommended. You cannot configure RAID 5 using the Group Manager GUI; however, it can be configured using the CLI. • Thin clones inherit the RAID preference, if any, of the template volume. You cannot set a separate RAID preference for a thin clone. • You can override automatic performance load balancing by enabling a RAID level preference 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. • To enable a volume RAID preference, make sure that 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. • If you disable a RAID preference on a volume, the group resumes automatic performance load balancing. Procedure To enable or disable a volume RAID preference: 1. Click Volumes. 2. Expand Volumes and select the volume name. 3. Click Modify settings and then click the Advanced tab to open the Modify volume settings - Advanced dialog box. 4. Select either: • Preferred RAID level under Volume RAID preference. • Automatic to disable a RAID preference 5. Click OK. PS Series Group Operations 131

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RAID Policy
Spare Disks
RAID Set Relationship
Best Practices
RAID 50
2
(6+1 ,6+,1, 6+1, 6+1, 6+1, 6+1) (3+1)
For selected
configurations
RAID 5
2
(12+1, 12+1, 12+1) (6+1)
Not for business-critical data
Table 31. 84–Drive
Configuration
shows the RAID set relationship for each RAID type in a 84-drive
configuration.
Table 31. 84–Drive
Configuration
RAID Policy
Spare Disks
RAID Set Relationship
Best Practices
RAID 6
2
(12+2) (12+2) (12+2) (12+2) (12+2) (10+2)
Yes
RAID 6
Accelerated
1 HHD
1 SSD
(12+2 HDD) (12+2 HDD) (12+2 HDD)
(12+2 HDD) (10+2 HDD) (12+2 SSD)
N/A
RAID 10
2
(7+7) (7+7) (7+7) (7+7) (7+7) (6+6)
Yes
RAID 50
2
(12+2) (12+2) (12+2) (12+2) (12+2) (10+2)
Not for business-critical data
RAID 5
2
(12+2) (12+2) (12+2) (12+2) (12+2) (10+2)
Not for business-critical data
Enable and Disable 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.
Prerequisites
The following prerequisites and considerations apply:
RAID 5 does not
offer
optimal data protection for business-critical data due to the higher risks of encountering a second drive
failure during a rebuild, and is therefore not recommended. You cannot
configure
RAID 5 using the Group Manager GUI; however,
it can be
configured
using the CLI.
Thin clones inherit the RAID preference, if any, of the template volume. You cannot set a separate RAID preference for a thin
clone.
You can override automatic performance load balancing by enabling a RAID level preference 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.
To enable a volume RAID preference, make sure that 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.
If you disable a RAID preference on a volume, the group resumes automatic performance load balancing.
Procedure
To enable or disable a volume RAID preference:
1.
Click
Volumes
.
2.
Expand
Volumes
and select the volume name.
3.
Click
Modify settings
and then click the
Advanced
tab to open the Modify volume settings – Advanced dialog box.
4.
Select either:
Preferred RAID level under
Volume RAID preference
.
Automatic
to disable a RAID preference
5.
Click
OK
.
PS Series Group Operations
131