I have a 2012(?) macmini at home and last night I backed up my HDD to Time Machine then moved the 1TB HDD to the 2nd bay and installed a new 250GB SSD into the 1st bay. I formatted the new drive to Mac OS Journaled and rebooted. Now I have tried to restore from Time Machine, but my backup (after excluded folders) is about 375GB. I have 2 questions:

  1. Is it possible to alter the time machine backup and delete folders I know I have backups elsewhere to get this under 250GB and then restore from that?
  2. If 1 is not possible, how do I reboot to use the original HDD again and redo my Time Machine backup for essential files only?

I've read other questions which say try a clean install, but it would take me days to re-configure my system the way I need it, so that is not an option.

I have a full backup on external HD as well as full cloud backup.

  • Although you can delete files/links out of the latest backup folder, it is not recommended. You can choose boot devices on startup by pressing and holding the Option (Alt) key. But isn't the system you booted still the old one, seeing that you just formatted the new drive?
    – sekdiy
    Commented Jun 2, 2016 at 8:18
  • It booted to the old system on first start-up after disk swap, but once I formatted the new disk, I think it only then mounted it as the system disk so on restart it used that and not the old.
    – TomC
    Commented Jun 2, 2016 at 8:34
  • Which means you didn't just format it, but actually installed an operating system onto it, right? But still, simply hold Option during boot (or alternatively choose a startup disk from the Settings app).
    – sekdiy
    Commented Jun 2, 2016 at 8:39
  • No as on startup it asked me to install or restore from Time Machine which was what I wanted to do. I could install the OS but thinking that is unnecessary if I'm going to restore over it later. You have partly answered my question with point 2 anyway. I'll try and go back to original HDD at home tonight and see if I can do it that way. Thanks
    – TomC
    Commented Jun 2, 2016 at 8:42
  • Cool. Actually, restoring from time machine implies an OS installation, as the backup only contains non-system files and folders. Your Mac has a recovery partition and even pulls the OS installer from the App Store on demand.
    – sekdiy
    Commented Jun 2, 2016 at 8:48

2 Answers 2


I've ended up answering my own question as follows:

  1. I wasn't able to delete files from the Time Machine backup and got the following message: The operation can't be completed because backup items can't be modified
  2. I rebooted using Command+R and then tried to restore from Time Machine. I kept getting errors saying the new drive was too small. I then installed OSX onto the new drive and then did the restore which worked ok.

Create a fusion drive using SSD and hardrive. It will work

  • 1
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