From: Steven Haigh <netwiz@crc.id.au>
To: linux-raid@vger.kernel.org
Subject: Re: Slow RAID 5 performance all of a sudden
Date: Tue, 26 Feb 2013 08:29:25 +1100 [thread overview]
Message-ID: <512BD7B5.6040408@crc.id.au> (raw)
In-Reply-To: <512BD686.2020109@s-tainment.co.za>
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On 26/02/2013 8:24 AM, Divan Santana wrote:
> On 02/25/2013 10:48 PM, Rudy Zijlstra wrote:
>> anything in dmesg or system log that gives a hint?
> Unfortunately not. I've checked it thoroughly.
> Next step may just have to be a reload. Not sure what caused this or
> that a reload will fix it.
>
> Either way it seems it may have to be the next step in troubleshooting
> this as I'm running out of ideas.
>
I had this recently and it turned out to be the PCIe controller dropping
its IRQ and going into some kind of fallback mode. When this was
happening, I'd be lucky to get 5-10Mb/sec read speed off the array
instead of the normal 100+Mb/sec.
Interestingly, the only thing I needed to do was relocate the card to
another slot and it hasn't happened since.
Don't just limit your search to md related stuff, check IRQs etc as
well. /proc/interrupts is a good start - maybe if you do use a card for
drives, try to not share IRQs between the card and other equipment...
--
Steven Haigh
Email: netwiz@crc.id.au
Web: http://www.crc.id.au
Phone: (03) 9001 6090 - 0412 935 897
Fax: (03) 8338 0299
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prev parent reply other threads:[~2013-02-25 21:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-13 9:06 Slow RAID 5 performance all of a sudden Divan Santana
2013-01-13 13:40 ` Mikael Abrahamsson
2013-02-25 20:10 ` Divan Santana
2013-02-25 20:48 ` Rudy Zijlstra
2013-02-25 21:24 ` Divan Santana
2013-02-25 21:29 ` Steven Haigh [this message]
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