Re: Very poor latency when using hard drive (raid1)

From: lkml@xxxxxxxxxxx
Date: Tue Apr 16 2013 - 02:49:59 EST


On 15/04/13 11:59, lkml@xxxxxxxxxxx wrote:
> There are 2 hard drives (normal, magnetic) in software raid 1
> on 3.2.41 kernel.
>
> When I write into them e.g. using dd from /dev/zero to a local file
> (ext4 on default settings), running 2 dd at once (writing two files) it
> starves all other programs that try to use the disk.
>
> Running ls on any directory on same disk (same fs btw), takes over half
> minute to execute, same for any other disk touching action.
>
> Did anyone seen such problem, where too look, what to test?
>
> What could solve it (other then ionice on applications that I expect to
> use hard drive)?

I got reply (by e-mail) suggesting to use XFS.
Thanks, possible for other/next server.

But I fell this should work correctly as well on ext4.




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