Additional Configuration Factors; Hot Spares; Clustering Considerations; Considerations For Optimal Raid Performance - Dell PowerVault 220S Manual

A REFERENCE GUIDE FOR OPTIMIZING DELL™ SCSI SOLUTIONS

Additional configuration factors

Hot Spares

Hot Spare functionality provides extra security availability and redundancy by replacing a
failed drive, allowing the rebuild of the degraded array to begin immediately. Both the
Adaptec and LSI based PERC controllers' support this feature, but a simple SCSI
controller would not. See the controller user's guide for details and limitations. Use of Hot
Spares is recommended whenever possible.

Clustering Considerations

In a cluster environment the cache being disabled on the controller poses a significant
performance impact to RAID 5 and RAID 50 configurations. If the system is to be clustered
RAID 10 is the optimal RAID level.
Cluster
Solutions

Considerations for Optimal RAID Performance

The PowerVault™ 22xS is capable of offering increased performance by allowing multiple
channels to connect to the storage enclosure. This ability can increase the performance
of most configurations by allowing a multi channel RAID controller to increase the
bandwidth of the SCSI bus. For more information see Table 4-2: PV22xS Configuration
Topologies vs RAID Level Performance.
Concatenated drives
RAID 0
RAID 1
RAID 10
RAID 5
RAID 50
PAGE 13
• Table 2-17: Cluster Solution Vs RAID Levels
Concatenated 0
Not Recommended
• Table 2-1 2-7: RAID Level Benefit (Generalized)
Clustering Multi Channel
None None
None Excellent
Moderate Excellent
Excellent Excellent
Moderate Moderate
Moderate Moderate
RAID Level
1 10 5
Recommended
Capacity
Relative Cost
Excellent
None
Excellent
None
Excellent
Excellent
Moderate
Moderate
Moderate
Moderate
VER A02
50
Possible
Scalability
Excellent
None
None
None
None
Excellent
Moderate
Moderate
11/17/2005