tlk888 Posted May 30, 2023 Share Posted May 30, 2023 (edited) Here is what's going on with my array while parity-sync: ----------------- Total size:14 TB Elapsed time:7 hours, 6 minutes Current position:315 GB (2.3 %) Estimated speed:12.4 MB/sec Estimated finish: 12 days, 17 hours, 12 minutes ----------------- My use case is backing up photos (~1.5M files) and running PLEXSERVER. I had a mixed array of HDD on USB2.0 and SATA-II ports. They are SATA-III drives but pluggin in SATA-II on my HP Z800 workstation. I had two questions (First time UNRAID user here so please bare with me): 1. What did I do wrong and why was the parity sync speed so slow? I did search in the forum, found some posts suggesting update CPU-C state to Always, but it didn't help either. 2. This HP Z800 board only SATA2 (3Gbps) and USB2.0, but it also had PCI-E 2.0 x16, should I get an HBA-i8 for these SATA-III drives and will it speed up the parity-sync? wst-diagnostics-20230529-2222.zip Edited May 30, 2023 by tlk888 Quote Link to comment
Solution JorgeB Posted May 30, 2023 Solution Share Posted May 30, 2023 USB 2.0 will always be pretty slow, max will be around 25MB/s for a single device, also we don't recommend using USB for array or pool drives Quote Link to comment
tlk888 Posted May 30, 2023 Author Share Posted May 30, 2023 (edited) Got it. I'll wait for the HBA board to shuck all USB drives to SATA-III ports. Curious: USB2.0 specs is 480Mbps so I'd expect ~50-55MB/s in reality. Why was it only 25MB/s? Edited May 30, 2023 by tlk888 Quote Link to comment
Kilrah Posted May 30, 2023 Share Posted May 30, 2023 3 minutes ago, tlk888 said: Curious: USB2.0 specs is 480Mbps so I'd expect ~50-55MB/s in reality. With overhead USB2 can only do 38-42MB/s at best. Then since parity operations require discs being in pretty tight sync there's likely some waits occurring due to buffering in various places. Quote Link to comment
tlk888 Posted May 31, 2023 Author Share Posted May 31, 2023 (edited) The good news: I moved USB2.0 disks to SATA3 and speed boosted. I saw 125MB/s on average and some time boosted to 611.8MB/s (!!!). Current position:4.17 TB (29.8 %) Estimated speed:605.6 MB/sec Estimated finish:4 hours, 31 minutes The bad news: It also introduced read errors and the drive (Disk 5, used to on USB.20) appeared as unmountable - it has data on it so I don't want to format. So my question: how do I get the drive into the array without losing data? Thanks for being patient with me Edited May 31, 2023 by tlk888 Quote Link to comment
itimpi Posted May 31, 2023 Share Posted May 31, 2023 The fact that the drive appears unmountable strongly suggests that the drive is not being presented exactly the same over SATA as it was over USB. This is not an uncommon occurrence. If that is the case it will almost certainly be necessary to start with the disk outside the array, and copy the data onto the array after which the disk then can be added and formatted as Unraid likes to have it formatted. 1 Quote Link to comment
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