[patch] giant-less quotas for UFS

Nicolas KOWALSKI Nicolas.Kowalski at imag.fr
Mon Apr 10 16:10:22 UTC 2006

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.


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