Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++ - Mailing list pgsql-performance

From Craig Ringer
Subject Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++
Date
Msg-id 4E4CA4BC.9050908@ringerc.id.au
Whole thread Raw
In response to Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++  (Ogden <lists@darkstatic.com>)
Responses Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++
Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++
List pgsql-performance
On 18/08/2011 11:48 AM, Ogden wrote:
> Isn't this very dangerous? I have the Dell PERC H700 card - I see that it has 512Mb Cache. Is this the same thing and
goodenough to switch to nobarrier? Just worried if a sudden power shut down, then data can be lost on this option. 
>
>
Yeah, I'm confused by that too. Shouldn't a write barrier flush data to
persistent storage - in this case, the RAID card's battery backed cache?
Why would it force a RAID controller cache flush to disk, too?

--
Craig Ringer

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