PROXMOX VE with ZFS poor simultaneous read writes


New Member
Sep 13, 2019
Hello Proxmox Team,

Im using Proxmox VE with ZFS installed on 10 1.2TB drives @ 10000 RPM with a partitioned Intel DC P4800 as ZIL and SLOG.

My issue is when I do a copy and paste in a file in Ubuntu the speeds jump to around 800 MB/s then it drops to 500 MB/s and hangs, it will hang for about 15 seconds then continue at this speed for about a few seconds then the cycle repeats until the file is copied. When I do an zpool iostat 1 1000. I can see it does not simultaneously do the reads and writes, the system would do the read operations and then followed by the write operations and continue cycling like this until the file is copied.

Im lost as to what can cause this issue, or is this the way ZFS works
Problem Solved

When ZIL is implemented, do not use any disk caching features. My Windows VM can now maintain 1 GB/s file copy, nominal speeds


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