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User profile for user: Heathen
Heathen Author
User level: Level 1
5 points

Time Machine back up and bootable drive

I have a late 2015 iMac with a drive that is slow and probably on its last legs. I also have a 2Tb Time Machine that is not able to do a full back up due to it being full. It apparently is not deleting the older backups to allow for a new one.

I am looking at buying a 2TB SSD drive to serve as my new TM backup disc and also a bootable drive for normal use. I want to replace the original internal disc with a new reliable and much faster one.

My question is how do I go about this?

Do I simply do a full backup to the new SSD then convert it to a bootable drive for daily use? The goal is really to have a new bootable drive, the initial back up serves only for migration of original disc data to the new one.

Thanks for any advice

Posted on Nov 13, 2021 11:09 AM

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User profile for user: Jack-19
Jack-19
User level: Level 8
46,008 points

Posted on Nov 13, 2021 12:28 PM

Welcome to Apple Support Communities.


First, I recommend getting a very large new backup drive. I recommend a SanDisk Professional G-DRIVE - Western Digital. You don’t need an SSD for backups, nor could you use the same drive for backups and to run macOS from. Regardless of which drive you choose, it needs to be formatted. Follow these steps:


  1. Go to Disk Utility (Finder > Go > Utilities)
  2. In Disk Utility, select “View” > “Show All Devices”.
  3. Select the top and non-indented drive in the external section of Disk Utility that matches the name of your external drive. 
  4. Click Erase
  5. Name: any name you want
  6. Format: Use Mac OS Extended (Journaled) if you are using macOS Catalina or earlier, or APFS if you are using macOS Big Sur or later.
  7. Scheme: GUID Partition Map
  8. Click Erase


Finally, setup Time Machine: Back up your Mac with Time Machine - Apple Support.


Next, use an external SSD to use as your new startup disk: How to Setup and Use an External SSD as y… - Apple Community.


Do NOT replace any internal drives. Let everything be external.


Jack

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Question marked as Top-ranking reply
User profile for user: Jack-19
Jack-19
User level: Level 8
46,008 points

Nov 13, 2021 12:28 PM in response to Heathen

Welcome to Apple Support Communities.


First, I recommend getting a very large new backup drive. I recommend a SanDisk Professional G-DRIVE - Western Digital. You don’t need an SSD for backups, nor could you use the same drive for backups and to run macOS from. Regardless of which drive you choose, it needs to be formatted. Follow these steps:


  1. Go to Disk Utility (Finder > Go > Utilities)
  2. In Disk Utility, select “View” > “Show All Devices”.
  3. Select the top and non-indented drive in the external section of Disk Utility that matches the name of your external drive. 
  4. Click Erase
  5. Name: any name you want
  6. Format: Use Mac OS Extended (Journaled) if you are using macOS Catalina or earlier, or APFS if you are using macOS Big Sur or later.
  7. Scheme: GUID Partition Map
  8. Click Erase


Finally, setup Time Machine: Back up your Mac with Time Machine - Apple Support.


Next, use an external SSD to use as your new startup disk: How to Setup and Use an External SSD as y… - Apple Community.


Do NOT replace any internal drives. Let everything be external.


Jack

Reply

Time Machine back up and bootable drive

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