<html><body><p><font size="2">Dear Spectrum Scale mailing list,</font><br><br><font size="2">I'm part of IBM Lab Services - currently i'm having multiple customers asking me for optimization of a similar workloads.</font><br><br><font size="2">The task is to tune a Spectrum Scale system (comprising ESS and CES protocol nodes) for the following workload: </font><br><font size="2"> A single Linux NFS client mounts an NFS export, extracts a flat tar archive with lots of ~5KB files. </font><br><font size="2"> I'm measuring the speed at which those 5KB files are written (`time tar xf archive.tar`). </font><br><font size="2"> </font><br><font size="2">I do understand that Spectrum Scale is not designed for such workload (single client, single thread, small files, single directory), and that such benchmark in not appropriate to benmark the system. </font><br><font size="2">Yet I find myself explaining the performance for such scenario (git clone..) quite frequently, as customers insist that optimization of that scenario would impact individual users as it shows task duration.</font><br><font size="2">I want to make sure that I have optimized the system as much as possible for the given workload, and that I have not overlooked something obvious.</font><br><br><br><font size="2">When writing to GPFS directly I'm able to write ~1800 files / second in a test setup. </font><br><font size="2">This is roughly the same on the protocol nodes (NSD client), as well as on the ESS IO nodes (NSD server). </font><br><font size="2">When writing to the NFS export on the protocol node itself (to avoid any network effects) I'm only able to write ~230 files / second.</font><br><font size="2">Writing to the NFS export from another node (now including network latency) gives me ~220 files / second.</font><br><br><br><font size="2">There seems to be a huge performance degradation by adding NFS-Ganesha to the software stack alone. I wonder what can be done to minimize the impact.</font><br><br><br><font size="2">- Ganesha doesn't seem to support 'async' or 'no_wdelay' options... anything equivalent available?</font><br><font size="2">- Is there and expected advantage of using the network-latency tuned profile, as opposed to the ESS default throughput-performance profile?</font><br><font size="2">- Are there other relevant Kernel params?</font><br><font size="2">- Is there an expected advantage of raising the number of threads (NSD server (nsd*WorkerThreads) / NSD client (workerThreads) / Ganesha (NB_WORKER)) for the given workload (single client, single thread, small files)?</font><br><font size="2">- Are there other relevant GPFS params?</font><br><font size="2">- Impact of Sync replication, disk latency, etc is understood. </font><br><font size="2">- I'm aware that 'the real thing' would be to work with larger files in a multithreaded manner from multiple nodes - and that this scenario will scale quite well.<br> I just want to ensure that I'm not missing something obvious over reiterating that massage to customers.</font><br><br><font size="2">Any help was greatly appreciated - thanks much in advance!</font><br><font size="2">Alexander Saupp</font><br><font size="2">IBM Germany<br></font><br><br><font size="2">Mit freundlichen Grüßen / Kind regards</font><br><br><b>Alexander Saupp</b><br><br><font color="#0055AA">IBM Systems, Storage Platform, EMEA Storage Competence Center</font><table border="0" cellspacing="0" cellpadding="0"><tr valign="top"><td class="small_font" width="800" colspan="4" valign="middle"><hr width="100%" size="2" align="left" style="color:#696969; "></td></tr>
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