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Level 1

5 points

Time Machine troubleshooting.

I'm trying to back up the working half of the 2 TB drive on my Mac Mini server (late 2012). I've checked to be sure that the internal backup (the other half of the drive) is excluded from the backup. Time Machine starts the backup OK, but reports that there's 1.11 TB to be backed up, when COMMAND-I on the drive reports that it is just a whisker smaller than 1 TB and only contains about 900 GB. I've run the disk doctor on both partitions, and both are given a clean bill of health. There's clearly something wrong, but is it important?

I'm running Mojave (ver. 10.14.1).

macOS Mojave (10.14.1)

Posted on Nov 23, 2018 6:46 PM

Best reply

trevoz

Level 4

1,990 points

Posted on Nov 26, 2018 3:16 AM

If Time Machine was enabled, but the Time Machine disk was not connected at some point, then it backs up to the local drive by making snapshots of the file system until such time as the Time Machine disk is connected again.

So, the amount to be backed up may be larger than the data shown as in use as your Mac counts the space used by snapshots as available storage. Even so, Time Machine stores snapshots only on disks that have plenty of free space, and it automatically deletes snapshots as they age or as space is needed for other things.

If you want to delete local snapshots manually, just turn Time Machine off and give it a few minutes to automatically delete them. When you turn Time Machine back on, it remembers your previous backup disk.

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Time Machine troubleshooting.

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