December 15, 20232 yr Hello, One of my drives is about to fail and I need to replace it asap. I have a new drive and am ready, but I want to ensure I perform the correct steps to help prevent data loss, if possible. System Details Unraid Version: 6.9.2 Parity Disk (1): 6 TB (PASSED) Data Disk 1: 4 TB (PASSED) Data Disk 2: 5 TB (FAILED) Issue Details I was trying to watch a movie on plex and it kept buffering at the same spot in the movie. I signed into my unraid instance for the first time in months and was greeted with a bunch of warnings. I checked my smart report and there are a number of issues for data disk 2. The latest that jumps out at me is "SMART overall-health self-assessment test result: FAILED! Drive failure expected in less than 24 hours. SAVE ALL DATA.". I have 3 array devices, Parity (PASSED), Disk 1 (PASSED), and Disk 2 (FAILED). Note: It is not showing a red ball yet, but guessing that'll change if the parity check finishes. A non-correcting parity check is currently running and doesn't look good so far: Total size:6 TB Elapsed time:25 minutes Current position:99.0 GB (1.7 %) Estimated speed:199.9 KB/sec Estimated finish:338 days, 21 hours, 51 minutes Sync errors detected:65 Steps Taken I reviewed the documentation. I bought a replacement 12 TB replacement drive. As my existing drives are relatively small and I'm running low on space, I would like to start preparing for larger drives. Therefore, I would like to perform a Parity Swap with the 2 step process. At a later date I will start replacing some of the older data drives with newer, larger ones. I created a diagnostics zip file and have attached it to this post. I started a parity check. Note: I started this with "Write corrections to parity" checked before later reading "It is also recommended that such a check is set as non-correcting as if a disk is having problems there is a chance of you corrupting your parity if you set such a check to be correcting". I stopped it about a minute after starting it with this option. It reported 1 error. I then started a non-correcting check. I read: "If you have single parity then you are not protected against a different drive failing during the upgrade process. If this happens then post to the forums to get advice on the best way to proceed to avoid data loss.", so that's what I'm doing. Next Steps Hope that I get some good advice from one of the many smarter-than-me people on this forum. My main concern is the parity check errors. If there were no parity errors, I think it would be safe to continue. However, I'm not sure what to do now. Once given the green light, follow Parity-Swap steps 1 through 15. For step 6, I will remove the old drive as I need the bay and cables for the new drive. I'm thinking to follow step 7 for the preclear, but would like confirmation that I should do this considering I only have 1 parity disk and there's always a chance another drive could fail before I replace the failed drive (I need to look up the instructions on how to do this). Any help would be greatly appreciated! odin-diagnostics-20231214-1925.zip
December 15, 20232 yr You should have 3.7TB data need to copy out from the fail disk, as parity show mismatch and parity operation in very slow speed, don't consider swap parity or rebuild route. To summarize what you should do, try your best to copy out most data ( 3.7TB ) from (1) a copy version from disk2, (2) a copy version from emulate /dev/md1 3.7T 3.1T 621G 84% /mnt/disk1 /dev/md2 4.6T 3.7T 947G 80% /mnt/disk2 Some detail for above suggestion - install UD plugin - stop array - set disk2 to no disk assign - then mount disk2 by UD and copy data to 12TB ( also mount by UD ), i.e. /mnt/disks/12TB/aaa/ , you may try rsync with --ignore-errors option, but if didn't help, you may need disk to disk block copy first https://serverfault.com/questions/494840/how-to-skip-files-with-read-error-in-it-when-copying-with-rsync-on-linux At this point, nothing have change, you can simple assign back 5TB disk to disk2, everything still as usual - then start array ( emulate disk2 ) , also copy to 12TB disk, i.e. /mnt/disks/12TB/bbb/ - consider which version is the best ( you can mix both whatever ) then copy to the 6TB disk - after all fine, then assign 6TB disk to disk2 and 12TB be parity and rebuild parity Edited December 15, 20232 yr by Vr2Io
December 15, 20232 yr Author Thank you for your reply. I won't shoot the messenger, but that's not good news. My understanding was that I would be safe if one drive failed with the parity drive, but it looks like my understanding was wrong. I'll have to get back to this after I resolve this issue. I will try to follow your steps this weekend. Luckily I have most of the important files backed up (maybe 75%), but unfortunately I've been a bit lazy with my backups lately. Hopefully combining your steps with my backups will allow me to recover most of the important files. I'm now expecting to lose at least some important files but I can only blame myself for not being on top of my backups.
December 16, 20232 yr Community Expert Assuming parity was valid, these errors with the bad disk don't count, you can just replace disk2 directly with a new one.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.