Very low disk performance on 5.x

[Eric Anderson]

Poul-Henning Kamp wrote:
> In message <427626DC.5030702 at centtech.com>, Eric Anderson writes:
> 
> 
>>Don't mean to be terse here, but I'm talking about the same test done an 
>>two different RAID5 configurations, with different disks, and not just 
>>me - other users in this very thread see the same issue..
> 
> 
> Uhm, if you are using RAID5 and your requests are not aligned and
> sized after the RAID5 you should *expect* read performance to be poor.
> 
> If you your request ends up accessing two different blocks even just
> once per stripe, this totally kills performance.

Wouldn't this be a problem for writes then too?



-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
A lost ounce of gold may be found, a lost moment of time never.
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