On 2/18/21 9:03 PM, Chris Murphy wrote: > Once everything else is figured out, you should consider converting > metadata to raid1c3.
Got it. > The new replacement is devid 0 during the replacement. The drive being > replaced keeps its devid until the end, and then there's a switch, > that device is removed, and the signature on the old drive is wiped. > Sooo.... something is still wrong with the above because there's no > devid 3, there's kernel and btrfs check messages saying devid 3 is > missing. > > It doesn't seem likely that /dev/sdc3 is devid 3 because it can't be > both missing and be the mounted dev node. It seems I was unclear. I removed the old drive prior to the replacement, hence degraded mode. A while ago, I imaged the drives, to see what I could do without risk (on another machine). Turns out I was able to mount the filesystem using -o ro,nologreplay,degraded and copy almost all files. A small number were unreadable/un-stat-able. Fortunately nothing critical, though the OS may well be unusable. (Also, in case you were wondering, memory testing has revealed no errors so far.) > If a tree log is damaged and prevents mount then, you need to make a > calculation. You can try to mount with ro,nologreplay and freshen > backups for anything you'd rather not lose - just in case things get > worse. And then you can zero the log and see if that'll let you > normally mount the device (i.e. rw and not degraded). But some of it > will depend on what's wrong. That doesn't work. It gives the same errors as when I tried to run check, but repeated once each for extent tree and device tree. It just can't get past this problem. At this point, I think it's best to just reinstall with a fresh filesystem, and not make the same mistakes. Thanks for the help, once again.