Re: Slow file transfer speeds with CFQ IO scheduler in some cases

From: Vitaly V. Bursov
Date: Sun Nov 09 2008 - 13:32:45 EST


Alexey Dobriyan wrote:
> On Sun, Nov 09, 2008 at 08:04:45PM +0200, Vitaly V. Bursov wrote:
>> I'm building small server system with openvz kernel and have ran into
>> some IO performance problems. Reading a single file via NFS delivers
>> around 9 MB/s over gigabit network, but while reading, say, 2 different
>> or same file 2 times at the same time I get >60MB/s.
>
> openvz kernels have very changed CFQ and, IIRC, this one-reader problem is
> fixed somewhere. Ask devel@xxxxxxxxxxx

That's why I've checked vanilla kernel also. It performs somewhat better,
but definitely shares same issues...

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