Mac back-ups

Personally, would keep the existing Time Machine Backup Drive as is. Insurance, incase you what or need to Revert the computer to older version of macOS.

Start a New Time Machine Backup to a new drive for the Big Sur OS. Be aware - Big Sur Time Machine Backup might convert an external Drive formatted as HFS Journaled to New APFS format. If using the Older TM Backup Drive - if converted to APFS might make Reverting or even accessing the Old Backups impossible .

Hi Mary208,

I presume you are using a external hard drive to backup your old Mac? Based on the assumption you are using a External HD, please follow the below to backup both your Old and New Mac.

When you use an external hard drive to back up different Macs, Time Machine automatically creates separate folders, one for each computer. If you ever need to restore data from the hard drive on any of your Macs, Time Machine understands which files match the specific computer.

To back up different Macs using Time Machine, you can:

Perhaps the simplest way is to attach the drive to one Mac, let Time Machine run a backup, and then disconnect the drive and repeat the steps on another Mac. In each case, Time Machine works behind the scenes to get the job done.

The drawback to this approach is that you manually have to connect and disconnect the hard drive to each computer. Still, as long as you set up Time Machine on each Mac, you're good to go.

Very Welcome and Thank you too :-))

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