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User profile for user: Red Ed
Red Ed Author
User level: Level 1
31 points

Reset Fusion Drive

After a failed attempt to upgrade my iMac (Late 2015, with Fusion Drive, running Catalina 10.15.7) to Monterey, and nearly bricking my device in the process, I was able to get back to a normal state of Catalina with one exception: the SSD is not mounting so I only have the HDD. I want to return to using the Fusion drive and am content with Catalina and have given up on Monterey. Attached are screen shots of what Disk Utility and About this Mac/Storage look like. How do I get from present state to use of the Fusion drive? I have a full Time Machine backup if needed. Thanks.

iMac 21.5″, macOS 10.15

Posted on Feb 4, 2022 11:08 AM

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User profile for user: den.thed
den.thed
User level: Level 10
82,066 points

Posted on Feb 4, 2022 11:13 AM

You will defiantly need that Time Machine backup after restoring the Fusion Drive.

see > https://support.apple.com/en-us/HT207584

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User profile for user: Red Ed
Red Ed Author
User level: Level 1
31 points

Feb 5, 2022 3:47 PM in response to den.thed

Thanks. I used that Terminal command diskutil resetFusion and it worked to reset my Fusion drive. However, it erased the disk in the process, and I was unable to return to Catalina as I had planned. After encountering several roadblocks, I was eventually able to install Monterey and recover my data from my backup, so I am all set.

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Reset Fusion Drive

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