* Working on improving error handling in the file object. This is not complete, but works well enough to find a few errors that have been causing us problems (notably, find is occasionally failing building the archive async manifest when system is under load).
* Found and squashed a nasty bug where file_copy was defaulted to ignore errors. There was also an issue in file_exists that was causing the test to fail when the file actually did exist. Together they could have resulted in a corrupt backup with no errors, though it is very unlikely.
* The archive-get function returns a 1 when the archive file is missing to differentiate from hard errors (ssh connection failure, file copy error, etc.) This lets Postgres know that that the archive stream has terminated normally. However, this does not take into account possible holes in the archive stream.
* If an archive directory which should be empty could not be deleted backrest was throwing an error. There's a good fix for that coming, but for the time being it has been changed to a warning so processing can continue. This was impacting backups as sometimes the final archive file would not get pushed if the first archive file had been in a different directory (plus some bad luck).
Tweaking a few settings after running backups for about a month.
* Removed master_stderr_discard option on database SSH connections. There have been occasional lockups and they could be related issues originally seen in the file code.
* Changed lock file conflicts on backup and expire commands to ERROR. They were set to DEBUG due to a copy-and-paste from the archive locks.
