Comments on: New way of handling RAID 5? http://itknowledgeexchange.techtarget.com/itanswers/new-way-of-handling-raid-5/ Wed, 22 May 2013 18:27:48 +0000 hourly 1 By: jjsmith http://itknowledgeexchange.techtarget.com/itanswers/new-way-of-handling-raid-5/#comment-48418 jjsmith Mon, 31 Jan 2005 09:50:07 +0000 #comment-48418 Write, or for that matter Read Cache does make a difference to performance. However Raid 5 and Raid 0+1 will always be different ( 0+1 better ). As a DBA I take this view, Raid 5 is ‘cheaper’ than 0+1 ( byte for byte ). As customers want an ever increasing amount of data on-line people start to worry about hardware cost. So, if the data is important RAID 1, if I/O speed is important, add in RAID 0. If cost takes priority over performace and resilience that use RAID 5.
If you are the kind of DBA that it constantly being told to improve performance then stick with RAID 0+1 as ‘you’ know exactly on which disk/spindle the data resides.
If in the future space comes under pressure and you need a stopgap solution, you can always change 0+1 to 5, but not the other way round.

Disk is so cheap now,that you should simply buy lots.

Regards
JJ

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