IBM DS5000, DS3000, DS4000 manual Recommended RAID Configurations

RECOMMENDED RAID CONFIGURATIONS

	RAID	RAID Array	Segment	Disk type
	level	size	size
Journal	1 or 10	As required	256	FC or SAS recommended
Meta Data	1 or 10	As required	256	FC or SAS recommended

∙Journal and Meta Data may reside in separate LUN‟s carved from the same RAID Array if required in small implementations. However, the ideal condition is separate LUN‟s tied to separate RAID groups for Journal and Meta Data. If possible, these two LUN‟s should be on a different storage system than the data LUN‟s.

∙StorNext can stripe across multiple LUN‟s. It is recommended that multiple RAID 1 Groups be used for Journal and Meta data rather than similarly sized RAID 10‟s. This allows multiple threads to be talking to disk offering enhanced performance.

Data	5	4+1	256	As required to meet performance
				criteria
	5	8+1	128	As required to meet performance
				criteria

∙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	6	4+2	256	As required to meet performance
				criteria
	6	8+2	128	As required to meet performance
				criteria

•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	13
© Copyright 2010, IBM Corporation. All rights reserved.