Very low fsyncs/second

rsmith8917

New Member
Apr 12, 2021
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I'm running proxmox on 3 HP Proliant DL20 Gen9 servers and all three are showing very poor fsyncs/second performance when running pveperf. These servers have 2 SATA HDDs (7200 RPM) with no RAID. Please see the example output from pveperf below. From the documentation, it looks like I should be expecting at least 200 fsyncs/second. Any guidance on how to troubleshoot this?

Code:
CPU BOGOMIPS:      55998.56
REGEX/SECOND:      4046918
HD SIZE:           93.99 GB (/dev/mapper/pve-root)
BUFFERED READS:    161.80 MB/sec
AVERAGE SEEK TIME: 11.97 ms
FSYNCS/SECOND:     53.48
DNS EXT:           33.55 ms
DNS INT:           35.31 ms
 
To me the value looks about right for a single HDD, my HDD (RAID1) do 70, my SSD (RAID10) do 900.
I don't think this is a Proxmox or configuration issue but just slow hardware instead. I read "value should be greater than 200" as "Proxmox requires at least 201 fsync/second", instead of "you can expect at least 200 fsync/second" (or did I not understand your post correctly?).
You might want to think about using write caching (with battery), using enterprise/datacenter SSDs, using a fast SLOG or using some form of RAID, if you want to be capable of more IOPS.
 

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