On Thu, Apr 2, 2020 at 8:36 PM Helper Son <helperson2000@xxxxxxxxx> wrote: > Thanks for the suggestion, the main problem is fixed on my end. At > this point I'm just wandering if taking this long to mount is normal > behavior and if there is anything else I can do to reduce the time, > but I suppose it's part of how btrfs works. It's normal on large file systems. There is work in progress to make this faster, but I'm not sure when it'll be merged. I think this does some short cuts when reading the chunk and extent trees at mount time. You could try switching to space_cache=v2 if you aren't already using it. It's safe to do: mount -o remount,clear_cache,space_cache=v2. Usually the rebuild goes fast, on 1T file system. Maybe it takes a minute on a 20T file system? Just a guess. I can't estimate how much it'll improve mount time, but it should somewhat at least. -- Chris Murphy
