[patch] giant-less quotas for UFS

[Eric Anderson]

Nicolas KOWALSKI wrote:
> Eric Anderson <anderson at centtech.com> writes:
> 
>> Nicolas KOWALSKI wrote:
>>> Kostik Belousov <kostikbel at gmail.com> writes:
>>>
>>>> On Mon, Apr 10, 2006 at 04:16:27PM +0200, Nicolas KOWALSKI wrote:
>>>>> Hello,
>>>>>
>>>>> Kostik Belousov <kostikbel at gmail.com> writes:
>>>>>
>>>>>> I already mailed about my development of the patch that
>>>>>> allows for UFS with quotas to operate without Giant. Sorry if the
>>>>>> repeat would be annoying.
>>>>> Does this patch improve the performance of a file server, using
>>>>> multiple disks, controlled by quotas, exported by NFS/Samba ?
>>>>>
>>>>> If so, I would be really interested: our file server (4.11, but
>>>>> perhaps 6.x soon), has some major slowdowns when one or multiple
>>>>> user/s exceed her/his quota ; this impact every user, even those
>>>>> working on another disk.
>>>> I don't think that patch shall have effect on this situation (quota
>>>> exceeded).
>> If you watch a tcpdump while this is happening, I'll bet you see the
>> client (over NFS) repeatedly trying to allocate blocks, and the server
>> returning ENOSPACE.  The load and cpu utilization on the server will
>> skyrocket while it gets hammered with requests for more space.  Not
>> sure what the solution is to this.
> 
> Yes, this is exactly what is happening. 
> 
> To add some precision, some students here use calculation applications
> that allocate a lot of disk space, ususally more than their allowed
> home quotas; when by error they launch these apps in their home
> directories, instead of their workstation dedicated space, it makes
> the server go to its knees on the NFS client side.

When you say 'to it's knees' - what do you mean exactly?  How many 
clients do you have, how much memory is on the server, and how many nfsd 
threads are you using?  What kind of load average do you see during this 
(on the server)?


Eric



-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
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