[patch] giant-less quotas for UFS

[Eric Anderson]

Nicolas KOWALSKI wrote:
> 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.
> 

In this case (which is what I suspected), try bumping up your nfsd 
threads to 128.  I set mine very high (I have around 1000 clients), and 
I can say there aren't really ill-effects besides a bit of memory usage 
(which you have plenty of).  I suspect increasing the threads will 
neutralize this problem for you.


Eric




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