[Lustre-discuss] Metadata performance question

[Ben Evans]

I've run into an interesting issue regarding metadata performance.

 

My MDS has ib on the front end, and a FC array on the back end in a RAID
10 configuration.

 

I have a number of clients creating 0 byte files in different
directories.  As the test runs, I can see the threads on the MDS idling
for 3-4 seconds before they all wake up, process whatever they need to
and go back to sleep.

 

I haven't been able to find a bottleneck in the system.  There's plenty
of memory, changing various parameters in the /proc directory on the
clients and on the MDS doesn't help much at all.  There's plenty of
bandwidth on the ib network and on the FC.  CPU and memory aren't overly
taxed (~50% max).  Yet I can only get about 10k file creates per second,
once I've created enough files so that caching 

 

The linux kernel is 2.6.18, with Lustre 1.6.5.

 

--

Ben Evans  ben at terascala.com

Principal Engineer

Terascala Inc.

Office:  508-588-1501 x223

www.terascala.com

 

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