Hey All,
I'm getting significantly lower read speeds compared to write speeds, and I'm seeking insights or suggestions to resolve this.
System Setup:
Test Procedure and Results:
Issue: While I'm unsure whether the write speeds are what you might expect for this setup, I believe read speeds are significantly lower than they should be.
Are there specific ZFS settings or TrueNAS configurations that I should check or modify to improve non-cached read performance?
Any assistance or guidance from the community would be greatly appreciated.
Thank you in advance!
I'm getting significantly lower read speeds compared to write speeds, and I'm seeking insights or suggestions to resolve this.
System Setup:
- TrueNAS running as VM with 16 Cores (EPYC 75F3 32-Core) and 124gb RAM
- 4 VDEV's of 6 drives in Raidz2
- Dataset for testing:
speedtest
(created specifically for this purpose with compression turned off). - ZFS Cache Setting: Set
primarycache=metadata
to disable data caching (only applied to the speedtest dataset).
Test Procedure and Results:
- Write Test:
- Command:
dd if=/dev/zero of=/mnt/bender/speedtest/tmp.dat bs=2048k count=50k
- Result: 107374182400 bytes transferred in 56.531521 secs (approx. 1.899 GB/s)
- Command:
- Read Test:
- Command:
dd if=/mnt/bender/speedtest/tmp.dat of=/dev/null bs=2048k count=50k
- Result: 107374182400 bytes transferred in 254.130370 secs (approx. 0.422 GB/s)
- Command:
Issue: While I'm unsure whether the write speeds are what you might expect for this setup, I believe read speeds are significantly lower than they should be.
Are there specific ZFS settings or TrueNAS configurations that I should check or modify to improve non-cached read performance?
Any assistance or guidance from the community would be greatly appreciated.
Thank you in advance!