Re: BUG #15110: Unable to backup database

Hello
This error message say your underlying filesystem returned less bytes than it should be. Usually this means storage was
corruptedand should be checked by sysadmins.
 
https://github.com/postgres/postgres/blob/REL_10_STABLE/src/backend/storage/smgr/md.c#L776

So i suggest shutdown database, then copy full PGDATA directory, check disks and filesystem and recover database from
backup.Or you may try enable zero_damaged_pages (this removes your data in such pages!) and copy the surviving data
(betterhaving another copy PGDATA).
 

regards, Sergei