Hello Spencer,

Monday, June 19, 2006, 5:47:21 PM, you wrote:

>> Hello Spencer,
>> Thursday, June 15, 2006, 11:48:57 PM, you wrote:
>> SS> On Thu, Robert Milkowski wrote:
>> >> Hello nfs-discuss,
>> >> 
>> >>   Sometimes on nfs servers I get below messages and then I have
>> >>   performance problems. What are they about and what can I do about
>> >>   this?
>> >> 
>> >> XXXX  rpcmod: [ID 851375 kern.warning] WARNING: svc_cots_kdup no slots 
>> >> free
>> >> XXXX  last message repeated 700353 times
>> SS> This is an error from the NFS server when it attempts to place
>> SS> a request into the duplicate request cache and finds that
>> SS> all of the ones in the duplicate request table are "in progress".
>> SS> The maximum for the duplicate request cache is 1024.
>> SS> The most effective way to increase the value is /etc/system
>> SS> and the variable would be: rpcmod:cotsmaxdupreqs 
>> I set it to 8192 and see some problems with nfsd+zfs - like almost all
>> threads hanging in ZFS and no actual IOs are happening while I can
>> issue IOs to the same zfs filesystems locally (see nfsd threads hang
>> in ZFS on zfs-discuss list).
>> I did set rpcmod:cotsmaxdupreqs=8192
>>           rpcmod:maxdupreqs=8192
>> Maybe it's too high?

SS> Are you still receiving the original error message your reported
SS> after making these changes? (the "no slots free" error)

No more errors - thanks for hint.

SS> If not, then the problem is in the local filesystem.
SS> What you have done is just allowed the NFS server to use the
SS> threads that it can create and not reject with error the incoming
SS> requests.

ok, thank you.

Best regards,
 Robert                            mailto:rmilkowski at task.gda.pl

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