Trying to create a time machine but it says' The backup disk needs 1.10 TB for the backup but only 4.99 TB are available'.

[Cangoose]

The only reason I can find is that I am running Catalina and therefore not the latest. There is plenty of space and I have formatted the ex hard drive but it won't back up. Please advise.

 

[TonyAguila]

The only reason I can find is that I am running Catalina and therefore not the latest. There is plenty of space and I have formatted the ex hard drive but it won't back up. Please advise.

macOS Catalina should be able to run Time Machine just fine. What is the size of the drive? You should also do a complete erase of the drive, and select APFS for the format. I’m not confident with the Disk Utility version that came with Catalina, so I recommend booting into Recovery and running Disk Utility from there (internet connection required). Or if you have access to a Mac with a newer version of macOS installed, you can do it there. The main advantage to doing it in Recovery is you are assured that it has the most current version of APFS.

I’m assuming also that your drive(s) to be backed up contain less than the capacity of the Time Machine drive. Do not encrypt the APFS format. You do that when you are setting it up in Time Machine (highly encouraged).

To give you a picture of the evolution of AFPS:

• macOS 10.12 has APFS version 0.3 or 249.x.x
• 10.13 has 748.x.x
• 10.14 has 945.x.x
• 10.15 has 1412.x.x
• 11 has 1677.x.x
• 12 has 1933.x.x until 12.2, thereafter 1934.x.x.
• 13 has 2142.x.x.

Source: The Eclectic Light Company Macs, Painting, and More

 

[Cangoose]

Thank you. I followed your instructions to the letter and yet this happened:

The backup disk needs 1.10 TB for the backup but only 5.00 TB are available. Select a larger backup disk or make the backup smaller by excluding files.

Clearly, I have enough space but it is still not working. If anyone else has an Idea, I would be grateful.