Re: choosing RAID level for xlogs

I would be very cautious about ever using RAID5, despite manufacturers' claims to the contrary. The link below is
authoredby a very knowledgable fellow whose posts I know (and trust) from Informix land. 

<http://www.miracleas.com/BAARF/RAID5_versus_RAID10.txt>

Greg Williamson
DBA
GlobeXplorer LLC


-----Original Message-----
From:    pgsql-performance-owner@postgresql.org on behalf of Anjan Dave
Sent:    Mon 8/15/2005 1:35 PM
To:    pgsql-performance@postgresql.org
Cc:
Subject:    [PERFORM] choosing RAID level for xlogs
Hi,



One simple question. For 125 or more checkpoint segments
(checkpoint_timeout is 600 seconds, shared_buffers are at 21760 or
170MB) on a very busy database, what is more suitable, a separate 6 disk
RAID5 volume, or a RAID10 volume? Databases will be on separate
spindles. Disks are 36GB 15KRPM, 2Gb Fiber Channel. Performance is
paramount, but I don't want to use RAID0.



PG7.4.7 on RHAS 4.0



I can provide more info if needed.



Appreciate some recommendations!



Thanks,

Anjan




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