On Sat, Nov 18, 2017 at 10:13 PM, Nazar Mokrynskyi [off-list ref] wrote:

That was eventually useful:

* found some familiar file names (mangled eCryptfs file names from times when I used it for home directory) and decided to search for it in old snapshots of home directory (about 1/3 of snapshots on that partition)
* file name was present in snapshots back to July of 2015, but during search through snapshot from 2016-10-26_18:47:04 I've got I/O error reported by find command at one directory
* tried to open directory in file manager - same error, fails to open
* after removing this lets call it "broken" snapshot started new scrub, hopefully it'll finish fine

If it is not actually related to recent memory issues I'd be positively surprised. Not sure what happened towards the end of October 2016 though, especially that backups were on different physical device back then.

Wrong csum computation during the transfer? Did you use btrfs send receive?

-- 
Chris Murphy