Poor disk IO on Xenserver 6.2

[Marko Lerota]

Roger Pau Monné <roger.pau at citrix.com> writes:

> El 29/08/14 a les 11.16, Marko Lerota ha escrit:
>> I have installed FreeBSD 10 release, stable and current on 
>> Xenserver 6.2 with latest patches. All of them have poor disk 
>> write speed. Performance from 12MBps - 25MBps. I tried it on
>> other servers but the performance is the same. Latest Debian
>> stable on the same machine have 300MBps disk speed. Am I missing
>> something after installation or this is the default speed?
>> 
>
> I've certainly seen higher speeds, around 25-35MB/s on my box, which is
> the same speed I can get with a Linux guest. Could you describe how you
> are running your tests?

You copy some *.tar.gz or *.iso file that have 600 MB. If it finish 
in 2-3 seconds than it's fine. If it runs 40 seconds than it's very, 
very bad. You can see current disk speed with 'iostat 1'. Today I have 
installed FreeBSD 10-Release on KVM and it runs smooth. Files are
copied at 150-300MB per second. That's how it should be. Suppose that 
you need to copy or sync files with another disk/partition very often. 
It would be very painful and long process. There is definitely something 
wrong here. 

-- 
Marko Lerota
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