[patch] giant-less quotas for UFS

[Nicolas KOWALSKI]

Eric Anderson <anderson at centtech.com> writes:

> Nicolas KOWALSKI wrote:
>>
>> 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)?

Sorry for the imprecision.

The server is a Dual-Xeon 2.8Ghz, 2GB of RAM, using SCSI3 Ultra320
76GB disks and controller. It is accessed by NFS from ~100 Unix
(Linux, Solaris) clients, and by Samba from ~15 Windows XP. The
network connection is GB ethernet.

During slowdowns, it's only from a NFS client view that the server
does not respond. For example, a simple 'ls' in my home directory is
almost immediate, but when it slows down, it can take up to 2 minutes.

On the server, the load average goes to 0.5, compared to a default
maximum of 0.15-0.20. The nfsd processus shows them in the state
"biowr" in top, but nothing is really written, because the quotas
system block any further writes to the user exceeding her/his quotas.

-- 
Nicolas