May 9, 20242 yr Struggling to troubleshoot a slow parity sync. Just swapped to a new system with a mini PC (i7, 64GB RAM) and USB 3.2 gen 2 DAS enclosure. A few things I noticed were: Initial transfer of my data over 1 gig network was at the expected speeds (110-250MB/s) but slowed to 5-30MB/s if the array was in use by docker apps on the new system Upon rebooting the new system, sometimes a disk (saw it happen to two) won't show up which requires another reboot to resolve Parity sync/check averages 5-8MB/s when array is in use by docker apps First issue was resolved by simply minimizing app use while the transfer finished. Second issue doesn't affect my data and I'm not surprised by with USB DAS. Though I did research and went with a TERRAMASTER D6-320 for a good USB controller and quality USB-C cable. It's also connected over SCSI. I know it's not recommended regardless, but hope it helps a bit. Third issue I can't seem to get around. I've rebooted and started a fresh sync, checked SMART data, done individual disk benchmarks, and ensured all docker apps didn't autostart. Nothing should be using my array but my parity sync is insanely slow. One of the drives is 5400RPM but that should still be ~100MB/s. Attached diagnostics downloaded after a reboot + letting parity sync for a bit. Edit: Ah, I see OOS12000G_000DSWBK - 12 TB (sdh) has a ton of read errors (which didn't show up on alerts or the Main page). Will try removing after transferring out the data and report back. Edit 2: Removed the drive from the array with a new config, parity sync is still the same speed so it wasn't that. Any clues? Adding new diagnostics from post-removal in case it helps. Edit 3: Writes to the array are about 90MB/s over SFTP during the parity sync, reads about the same. Definitely not the disks from what I see. srv-host-0-diagnostics-20240509-0152.zip srv-host-0-diagnostics-20240509-0248.zip Edited May 9, 20242 yr by Daniel Thiberge
May 9, 20242 yr Community Expert Solution Nothing obvious logged, please note that USB is not recommended for array and pool devices, for many reasons, including performance.
May 9, 20242 yr Author 31 minutes ago, JorgeB said: Nothing obvious logged, please note that USB is not recommended for array and pool devices, for many reasons, including performance. It was the USB-C cable haha. Thought I bought a nice one but a cheaper one brought the expected speeds.
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