Re: SSD + RAID - Mailing list pgsql-performance

From Matthew Wakeling
Subject Re: SSD + RAID
Date
Msg-id alpine.DEB.2.00.0912081421120.25000@aragorn.flymine.org
Whole thread Raw
In response to Re: SSD + RAID  (Greg Smith <greg@2ndquadrant.com>)
Responses Re: SSD + RAID
List pgsql-performance
On Fri, 13 Nov 2009, Greg Smith wrote:
> In order for a drive to work reliably for database use such as for
> PostgreSQL, it cannot have a volatile write cache.  You either need a write
> cache with a battery backup (and a UPS doesn't count), or to turn the cache
> off.  The SSD performance figures you've been looking at are with the drive's
> write cache turned on, which means they're completely fictitious and
> exaggerated upwards for your purposes.  In the real world, that will result
> in database corruption after a crash one day.

Seagate are claiming to be on the ball with this one.

http://www.theregister.co.uk/2009/12/08/seagate_pulsar_ssd/

Matthew

--
 The third years are wandering about all worried at the moment because they
 have to hand in their final projects. Please be sympathetic to them, say
 things like "ha-ha-ha", but in a sympathetic tone of voice
                                        -- Computer Science Lecturer

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