Re: speedup ceph / scaling / find the bottleneck

[Stefan Priebe <s.priebe@profihost.ag>]

Am 06.07.2012 20:17, schrieb Gregory Farnum:
>> Am 06.07.2012 um 19:11 schrieb Gregory Farnum <greg@inktank.com>:
>>> I'm interested in figuring out why we aren't getting useful data out
>>> of the admin socket, and for that I need the actual configuration
>>> files. It wouldn't surprise me if there are several layers to this
>>> issue but I'd like to start at the client's endpoint. :)
>>
>> While I'm on holiday I can't send you my ceph.conf but it doesn't contain anything else than the locations and journal dio false for tmpfs and /var/run/ceph_$name.sock
>
> Is that socket in the global area?
Yes

 > Does the KVM process have
> permission to access that directory?
Yes it is also created if i skip $name and set it to /var/run/ceph.sock

>>> Regarding the random IO, you shouldn't overestimate your storage.
>>> Under plenty of scenarios your drives are lucky to do more than 2k
>>> IO/s, which is about what you're seeing....
>>> http://techreport.com/articles.x/22415/9
>> You're fine if the ceph workload is the same as the iometer file server workload. I don't know. I've measured the raw random 4k workload. Also I've tested adding another osd and speed still doesn't change but with a size of 200gb I should hit several osd servers.
> Okay — just wanted to point it out.

Thanks also with sheepdog i can get 40 000 IOp/s.

Stefan

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