Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++

From: Craig Ringer <ringerc(at)ringerc(dot)id(dot)au>
To: Ogden <lists(at)darkstatic(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org, Greg Smith <greg(at)2ndquadrant(dot)com>
Subject: Re: Raid 5 vs Raid 10 Benchmarks Using bonnie++
Date: 2011-08-18 05:35:56
Message-ID: 4E4CA4BC.9050908@ringerc.id.au
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: 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 good enough 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

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Craig Ringer 2011-08-18 05:45:48 Re: tunning strategy needed
Previous Message Craig Ringer 2011-08-18 05:32:34 Re: Calculating statistic via function rather than with query is slowing my query