(We opened case 04128417 for this, but it was closed due to support team load.)
We are using VBR 9.5.4 Community Edition to backup 4 Windows guests on an ESXi 6.5 host. Backups are to USB disks shared off a Windows PC, 1 job and disk/repository per day of the week, using a reverse incremental scheme. So each disk/repository gets used once a week, every week.
This mostly has been working fine, but one of the Friday backup suddenly started a new backup chain, with no explanation logged.
- The previous week had been missed, as the disk hadn't been available. (But this has happened before and has not affected subsequent backups.)
- The week before that had run normally and successfully.
We have had two broken backup chains before this, on different disks, but in those cases the reason was somewhat more clear, e.g., immediately cancelling the previous backup (we won't do that again...)
How can we determine what caused this break in the backup chain, so we can avoid it in the future?