Continuing to use Time Machine to backup External hard drives from macOS 10 with macOS 11

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Continuing to use Time Machine to backup External hard drives from macOS 10 with macOS 11

Hi all,

I have recently upgraded from a White MacBook late 2007 (macOS 10.7.5) to a MacBook Air M1 2020 (macOS 11.2.3).

I have several external usb hard drives. For each drive, I have a dedicated Time Machine backup hard drive. When a particular drive and its backup are mounted to the new MacBook Air, (and ‘use backup disk’ is selected) the Time Machine App doesn’t show the historical backup. It is as if it doesn’t recognise the backup. I could just back up the drive and start from scratch now, but before I do this, I’d like to know if it is possible to fix this so that I can continue using the old backups rather than start a fresh backup!

Thanks

MacBook Air 13″, macOS 11.2

Posted on May 7, 2021 7:34 AM

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Answer 1

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PRP_53

Level 10

91,477 points

May 7, 2021 8:00 AM in response to Lemonic

Would Suggest using a New empty drive. Big Sur requires the Time Machine Backup Drive be formatted in the New APFS format. It will offer to do that for you when setting it up for the first time on the new computer. For that reason, the suggestion for a new empty drive. Should you decide to use the existing drive - TM will still convert the drive to APFS and thusly all the old TM Backups are basically lost.

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