How to reset Time Machine from scratch

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Level 1

16 points

How to reset Time Machine from scratch

My Time Machine backups have been made to a Synology DiskStation for several years. I recently discovered an anti-virus program had been automatically quarantining many of my Time Machine backups, rendering them unusable. I tried to restore these from quarantine but that just made a bigger mess of the backups.

Since even before this, the Time Machine backups only went back less than two months, I decided to just start a new Time Machine backup from scratch. So I removed all the old files from my "TimeMachine BUs" folder on the Synology DiskStation, leaving the folder empty. However, when I initiated a new Time Machine backup it still said my "TimeMachine BUs" folder on the Synology DiskStation has just 368 BG of 1.1 TB available. Since it is trying to create an entirely new backup it fails with a not enough space available message.

I tried renaming the /Library/Preferences/com.apple.TimeMachine.plist file, and also selecting a new and empty "TM BUs" folder on the Synology DiskStation for Time Machine to use but each time I attempt a new Time Machine backup it keeps showing 368 BG of 1.1 TB available. It seems that Time Machine has this usage information cached some where and isn't getting refreshed.

How can I reset Time Machine to start all over and forget all previous backups and storage usage?

This is on a MacBook Pro with macOS Sierra 10.12.5 (16F73)

-Ray

MacBook Pro (Retina, 13-inch, Late 2013), macOS Sierra (10.12.5)

Posted on Jul 18, 2017 10:57 AM

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Answer 1

John Galt

Level 10

146,402 points

Jul 18, 2017 12:59 PM in response to Ray-T

Non-Apple NAS devices are unsuitable for use with Apple's Time Machine. To learn how to use Time Machine please read Use Time Machine to back up or restore your Mac - Apple Support.

Assuming your reply – that you have been using Time Machine with your "Synology DiskStation" for years so that must not be correct – please refer to the preceding comment.

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Answer 2

Jul 18, 2017 11:16 AM in response to Ray-T

This should help you. Sadly Pondini passed away a couple of years, but the information should still be valid.

http://pondini.org/TM/12.html

P.S.: There is no need to use an anti-virus program on a Mac and I would never trust it when it is telling me that Time Machine backups are not usable.

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Answer 3

Ray-T Author

Level 1

16 points

Jul 18, 2017 12:18 PM in response to Georg Portenkirchner

George,

Thanks but I don't see anything in those instructions (gray box, for deleting from a NAS) that I haven't already done, although I did use the file editing tools of my NAS to delete (actually move to another location) all the files in my Time Machine folder. But some how, Time Machine still thinks the files are present.

I believe there is some cached data on my local machine that Time Machine is not refreshing. Probably because it can't complete a new (full) backup due what it believes is insufficient space. Although there is over 1 TB available, Time Machine thinks there is only 368 GB available and needs over 400 GB to do an initial backup.

BTW, The AV program was running on my NAS not my Mac.

Thanks

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