Time Machine Oddness

[bayswater]

Any suggestions on how to resolve this TM anomaly are appreciated. This is on a MBP running 10.13.6

TM reports that it has not done a backup since July 4. If it tell it to do one now, it says the backup volume is not available.

I can connect to the volume used for TM using the Finder's Connect to Servers command. The TM backup bundle appears and is dated July 14. I can enter TM and restore a screenshot file that is no longer on this Mac that has a creation date later than July 4. Obviously TM has backed up files later than July 4

If I tell TM to do a backup again, with the volume mounted and open on the desktop, the same message saying the volume is not available appears.

Another Mac also running 10.13.6 in the same room also backs up to this volume without incident.

Restart does not help.

[mikehalloran]

Do you have only the one backup volume for this Mac?

[bayswater]

Yes, I've only ever had one. It's connected to the wifi router. I have backups on it for 4 Macs, two of which don't exist any more, so there are still three Macs using this volume for backup, including the one of concern.

There are two other Macs on the network, but they each have a dedicated physically connect TM volume.

I also use this volume as a temporary file repository for things I have to move off line with all 5 Macs. And it works fine for all those other things. The problem is only with this MBP and only for using TM. So it would seem to be something in the MBP itself. I'm reluctant to mess around with settings and prefs for fear of losing continuity in the backup series for this one Mac.

[mikehalloran]

The best way—if the system lets you—is to let it create a new backup and have it ask you to inherit the old one. Click Yes.

Otherwise, TM can create a new backup leaving the old one intact. You then delete the old one on that drive — if you have the drive space. If you don't have enough space, the old backup may have to be removed first. I hate it when that happens but it has a few times over the years.

Deleting the old backup is a multi-step PIA but it is doable and I know how. A newer backup will not conflict with removing the old one.

[bayswater]

Thanks for the suggestions.

I'll try a new backup that inherits the old one. Problem is the drive is getting full and is likely to start deleting the very oldest backups, which is fine, but there may not be room to create a new backup with he contents of the old one.

Also, if TM can't see the old backup to use it, it's seems unlikely it will be able find it to inherit the contents. All this despite that fact that it IS actually doing backups.

Maybe time to just get a new drive and start a new backup.

I have a terminal command somewhere to delete old back-ups. It's an overnight operation IIRC.