Investigate case where backup completes successfully, however, SQLite files may be empty

What's the issue?
During some recent volume testing, we noticed a situation where 'cbbackupmgr' completed a backup "successfully", however, upon attempting to read/restore/merge the backup, it became evident that the backup was invalid/incomplete (contained empty SQLite files).

Now it's worth noting that there appeared to be some disk failures/NFS IO errors during this testing. That's not to excuse this though; we shouldn't be hitting/highlighting these IO errors at the time of backup (if possible).

We should investigate why we were able to "successfully" complete a backup which contained empty SQLite files.