RAID LEVEL Migration on LIVE MSA 1000

[Shery Vijayan]

We have a DL580 Cluster with MSA1000 on Fiberchannel running Sybase ASE Server in production.
The MSA Logical 3 drives ( 10Gb, 400GB and 150GB) were configured as RAID 6(ADG).
As we are facing performance issues , we would like to migrate the logical drives to RAID 1+0.
Please advice whether this can be done online as the server is live.
What will be impact on the live database performance in this case .
Appreciate an immediate assistance.

[James Muell]

It is dubious whether you could migrate a live database. Downtime to move the files or file structures to new luns would be more practical. The time this takes depends on how large the database is.
Your description leads me to believe that all 3 logicals are from the same Array. Is that correct? If so, that could be part of the cause of pour performance. Best practices for database clusters would be to segment database functions on separate disk arrays. Overall you will be limited in performance on the MSA1000 because all data is transmitted through 1 controller due to the Active - passive nature of the system. Going to a single RAID 1+0 would not necessarily give you much more performance if some of the database functions are in contention with each other for controller time. HP MSA1000 optimum array sets for Raid 5 are w/ 7 disks. You may be better off adding disks, configuring other array groups and logicals and moving parts of the database i.e. tempdb files, logs, etc to other logical drives.