Not enough space for first time back up in time machine (again)

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Not enough space for first time back up in time machine (again)

Hello. I am trying to do an initial backup of a 2018 Mac Mini with a 256 GB HD to an external 4 TB 2.5" HDD. I have completely wiped the drive, partitioned to two 2-TB partitions and reformatted both to APFS and apple GUID. When I try to run the initial backup, it gets hung up for many hours on "backing up 166.99 of 208.38 GB" then eventually fails and tells me there is not enough room on the backup disk.

When I look in disk utility, it tells me 1.46 TB have been used. This number gradually creeps up until it fails. The only thing that should be on this disk is the backup of my 209 GB from my Mac Mini. Any thoughts? Thanks in advance!

Posted on Jun 14, 2022 6:31 AM

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Answer 1

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srbwanderer

Community Specialist

Jun 15, 2022 9:22 AM in response to SGMReno

Hello SGMReno,

It is possible that whatever method was used to create the partitions caused some sort of issue.

We would suggest that you go ahead and completely erase and reformat the drive again. Once that is complete, use the steps outlined here to create separate partitions: Add, delete, or erase APFS volumes in Disk Utility on Mac - Apple Support (AL)

More information about the types of disks that can used is available here. Make sure that the disk meets all the requirements outlined: Types of disks you can use with Time Machine on Mac - Apple Support (AL)

Cheers.

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Answer 2

SGMReno Author

Level 1

8 points

Jun 16, 2022 2:16 PM in response to srbwanderer

Thanks srbwanderer. I used a different metod to troubleshoot the backup disk: I employed a completely different drive which was NOT partitioned. I formatted it as APFS prior to running the initial backup. Same result as the other drive. I then engaged Apple support. They had me run the same steps again (reformat the drive, run the backup again, same result) and escalated me to a Senior tech. Nothing he suggested worked, so I eventually just cloned my SSD for backup (instead of using Time Machine), upgraded to Montery, then ran the backup again. Viola, all is well and the first backup succeeded in 35 minutes and used the appropriate amount of space on the backup drive!

So, something was locking up or leaking during the backup under Big Sur which was filling up the backup drive but not completing the backup. We still don't know how or why, but the upgrade to Montery has solved the issue. 🤷🏼‍♂️

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Not enough space for first time back up in time machine (again)

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