Am Mi., 17. März 2021 um 03:59 Uhr schrieb Chris Murphy <li...@colorremedies.com>: > > On Tue, Mar 16, 2021 at 7:39 PM Qu Wenruo <quwenruo.bt...@gmx.com> wrote: > > > Using that restore I was able to restore approx. 7 TB of the > > > originally stored 22 TB under that directory. > > > Unfortunately nearly all the files are damaged. Small text files are > > > still OK. But every larger binary file is useless. > > > Is there any possibility to fix the filesystem in a way, that I get > > > the data less damaged? > > > > From the result, it looks like the on-disk data get (partially) wiped out. > > I doubt if it's just simple controller failure, but more likely > > something not really reaching disk or something more weird. > > Hey Qu, thanks for the reply. > > So it's not clear until further downthread that it's bcache in > writeback mode with an SSD that failed. And I've probably > underestimated the significance of how much data (in this case both > Btrfs metadata and user data) and for how long it can stay *only* on > the SSD with this policy.
Sorry Chris. I might have expressed this wrongly. But the btrfs-filesystem was never on bcache. On bcache was a xfs-filesystem that I backed up (rsynced) to the btrfs-filesystem when everything went wrong. And I quickly gave up hope for that xfs afterwards, due to the (lost) cached data of the directory-structure. That's why I'm focusing on getting the backup on the btrfs-filesystem back. But the possibility that some data is really wiped out or as Qu said, that something is not reaching the disk gives me a direction to investigate further. Maybe the raid-enclosure or the FC got damaged (I ruled that out in the beginning). Eventually a failed raid-rebuild or so. That would explain why so much data is missing. Thank you. Sebastian
