NFS behavior on a ZFS dataset with no quota remaining

[Robert Schulze]

Hi,

Am 17.04.2014 06:01, schrieb Garrett Wollman:
> Recently one of our users managed to constipate one of our NFS servers
> in an odd way.  They hit the quota on their dataset, and rather than
> having all of their writes error out as they should have, the NFS
> server instead stopped responding to all requests.

this behaviour is present since the beginnings of ZFS in FreeBSD. When a 
quota limit is reached, local reads are performing very bad or stall 
completely. The issue in combination with NFS is even more annoying, 
I've seen that happen quite often. IMHO this is a flaw which can easily 
be used to DOS any NFS server with quotas set.

with kind regards,
Robert Schulze

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