New SPECsfs2008 CIFS/SMB vs. NFS (again) – chart of the month

The above chart represents another in a long line of charts on the relative performance of CIFS[/SMB] versus NFS file interface protocols. The information on the chart are taken from vendor submissions that used the same exact hardware configurations for both NFS and CIFS/SMB protocol SPECsfs2008 benchmark submissions.

There are generally two charts I show in our CIFS/SMB vs. NFS analysis, the one above and another that shows a ops/sec per spindle count analysis for all NFS and CIFS/SMB submissions.  Both have historically indicated that CIFS/SMB had an advantage. The one above shows the total number of NFS or CIFS/SMB operations per second on the two separate axes and provides a linear regression across the data. The above shows that, on average, the CIFS/SMB protocol provides about 40% more (~36.9%) operations per second than NFS protocol does with the same hardware configuration.

However, there are a few caveats about this and my other CIFS/SMB vs. NFS comparison charts:

• The SPECsfs2008 organization has informed me (and posted on their website) that  CIFS[/SMB] and NFS are not comparable.  CIFS/SMB is a stateful protocol and NFS is stateless and the corresponding commands act accordingly. My response to them and my readers is that they both provide file access, to a comparable set of file data (we assume, see my previous post on What’s wrong with SPECsfs2008) and in many cases today, can provide access to the exact same file, using both protocols on the same storage system.
• The SPECsfs2008 CIFS/SMB benchmark does slightly more read and slightly less write data operations than their corresponding NFS workloads. Specifically, their CIFS/SMB workload does 20.5% and 8.6% READ_ANDX and WRITE_ANDX respectively CIFS commands vs. 18% and 9% READ and WRITE respectively NFS commands.
• There are fewer CIFS/SMB benchmark submissions than NFS and even fewer with the same exact hardware (only 13). So the statistics comparing the two in this way must be considered preliminary, even though the above linear regression is very good (R**2 at ~0.98).
• Many of the submissions on the above chart are for smaller systems. In fact 5 of the 13 submissions were for storage systems that delivered less than 20K NFS ops/sec which may be skewing the results and most of which can be seen above bunched up around the origin of the graph.

And all of this would all be wonderfully consistent if not for a recent benchmark submission by NetApp on their FAS8020 storage subsystem.  For once NetApp submitted the exact same hardware for both a NFS and a CIFS/SMB submission and lo and behold they performed better on NFS (110.3K NFS ops/sec) than they did on CIFS/SMB (105.1K CIFS ops/sec) or just under ~5% better on NFS.

Luckily for the chart above this was a rare event and most others that submitted both did better on CIFS/SMB. But I have been proven wrong before and will no doubt be proven wrong again. So I plan to update this chart whenever we get more submissions for both CIFS/SMB and NFS with the exact same hardware so we can see a truer picture over time.

For those with an eagle eye, you can see NetApp’s FAS8020 submission as the one below the line in the first box above the origin which indicates they did better on NFS than CIFS/SMB.

Comments?

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The complete SPECsfs2008  performance report went out in SCI’s March 2014 newsletter.  But a copy of the report will be posted on our dispatches page sometime next quarter (if all goes well).  However, you can get the latest storage performance analysis now and subscribe to future free newsletters by just using the signup form above right.

Even more performance information on NFS and CIFS/SMB protocols, including our ChampionCharts™ for file storage can be found in  SCI’s recently (March 2014) updated NAS Buying Guide, on sale from our website.

As always, we welcome any suggestions or comments on how to improve our SPECsfs2008 performance reports or any of our other storage performance analyses.