I have a turnkey instance a few years old (vTiger).

It has been backing up daily and has ~1500 backup sessions.

(An aside is I recently reset to max 100 sessions but it has not cleared the excess sessions still kept.)

Lately backups appear to have been failing. I checked it a month ago and a couple of days had been missed in a row.

Then recently I checked in and a whole month had been missed. 

I manually did a back up and it resumed a failed session.

It backed that session up successfully, but the auto back-ups still seem to be failing, though set. One auto back-up has completed and now it is back to skipping sessoins, obviously failing.

Any advice? I am going to try a backup with --disable-resume option set next.

Feedback appreciated. Thanks.