We return now to our ongoing quest to understand the difference between CIFS and NFS performance in the typical data center. As you may recall from past posts and our newsletters on this subject, we had been convinced that in SPECsfs 2008 CIFS had almost 2X the throughput of NFS in SPECsfs 2008 benchmarks. Well as you can see from this updated chart this is no longer true.
Thanks to EMC for proving me wrong (again). Their latest NFS and CIFS result utilized a NS-G8 Celerra gateway server in front of V-Max backend using SSDs and FC disks. The NS-G8 was the first enterprise class storage subsystem to release both a CIFS and NFS SPECsfs 2008 benchmark.
As you can see from the lower left quadrant all of the relatively SMB level systems (under 25K NFS throughput ops/sec) showed a consistent pattern of CIFS throughput being ~2X NFS throughput. But when we added the Celerra V-Max combination to the analysis it brought the regression line down considerably and now the equation is:
CIFS throughput = 0.9952 X NFS throughput + 10565, with a R**2 of 0.96,
what this means is that CIFS and NFS throughput are roughly the same now.
When I first reported the relative advantage of CIFS over NFS throughput in my newsletter I was told that you cannot compare the two results mainly because NFS was “state-less” and CIFS was “state-full” and a number of other reasons (documented in the earlier post and in the newsletter). Nonetheless, I felt that it was worthwhile to show the comparison because at the end of the day whether some file happens to be serviced by NFS or CIFS may not matter to the application/user, it should matter significantly to the storage administrator/IT staff. By showing the relative performance of each we were hoping to help IT personnel to decide between using CIFS or NFS storage.
Given the most recent results, it seems that the difference in throughput is not that substantial irregardless of their respective differences. Of course more data will help. There seems to be a wide gulf between the highest SMB submission and the EMC enterprise class storage that should be filled out. As Celerra V-Max is the only enterprise NAS to submit both CIFS and NFS benchmarks there could still be many surprises in store. As always, I would encourage storage vendors to submit both NFS and CIFS benchmarks for the same system so that we can see how this pattern evolves over time.
The full SPECsfs 2008 report should have went out to our newsletter subscribers last month but I had a mistake with the link. The full report will be delivered with this months newsletter along with a new performance report on Exchange Solution Review Program and storage announcement summaries. In addation, a copy of the SPECsfs report will be up on the dispatches page of our website later next month. However, you can get this information now and subscribe to future newsletters to receive future full reports even earlier, just email us at SubscribeNews@SilvertonConsulting.com?Subject=Subscribe_to_Newsletter.
As always, we welcome any suggestions on how to improve our analysis of SPECsfs or any of our other storage system performance results.