Recommended Raid Configurations - IBM DS4000 Installation Manual

Storage Controller A
Controller B

RECOMMENDED RAID CONFIGURATIONS

RAID
level
Journal 1 or 10
Meta Data 1 or 10
• Journal and Meta Data may reside in separate LUNS carved from the same RAID Array if
required in small implementations. However, the ideal condition is separate LUNS tied to
separate RAID groups for Journal and Meta Data. If possible, these two LUNS should be
on a different storage system than the data LUNS.
• StorNext can stripe across multiple LUNS. It is recommended that multiple RAID 1 Groups
be used for Journal and Meta Data rather than similarly sized RAID 10s. This allows
multiple threads to be talking to disk offering enhanced performance.
Data
• Data – Based upon StorNext file system header block size of 1MB, it is important to keep
this in mind when selecting the segment size. RAID Array (also called Group) size and
appropriate segment size should result in stripe size of 1MB. This will result in optimizing
write throughput speeds. Ex. RAID5 4+1 (4 data) drives x 256K (seg size) = 1 MB Write
stripe & RAID5 8+1x128K (seg size) = 1 MB stripe.
• Note – this rule does not apply to all deployments and could be dramatically different for
oil and gas industry deployments among others. It is very important to understand the I/O
block size of the applications sitting atop the StorNext File system.
Data
• Some customer applications may specify SATA drives and/or require additional RAID
protection. The DS3000/DS4700/DS5000 storage servers offer additional levels of RAID
protection if desired.
Digital Media Storage Solution Installation Guide
© Copyright 2010, IBM Corporation. All rights reserved.
Up to 8
Up to 8
RAID Array
size
As required
As required
5 4+1
5 8+1
6 4+2
6 8+2
All ports see all MDC and client ports
All ports see all MDC and client ports
Segment
size
256 FC or SAS recommended
256 FC or SAS recommended
256 As required to meet performance
criteria
128 As required to meet performance
criteria
256 As required to meet performance
criteria
128 As required to meet performance
criteria
Disk type
16