resetFusion: newfs_apfs unable to format disk - invalid argument

[eccentricglow]

Hello everyone,

Can someone give me a hint as to what is going wrong with setting up a fusion drive here? I've recently acquired a 2017 iMac for free (woohoo) and I upgraded the storage to a 2TB Apple blade SSD and a IronWolf Pro 20TB hard drive to use as a server / backup computer.

The issue seems to be with creating the APFS container on the SSD while running the resetFusion command. I've ran FirstAid on both drives -- no issues reported. I've also created apfs volumes with disk utility on both of the drives and went off without a hitch.

I've enclosed a screenshot of the process to show exactly what happened:

 

[Bigwaff]

You should reconsider creating a Fusion Drive. A Fusion Drive uses the SSD as cache for fast access to frequently accessed files on HDD. That is why Fusion Drive SSD are small capacity, e.g. 128GB. Your 2TB SSD is an enormous cache. Plus, Fusion Drive’s are notorious for poor reliability. Just use the drives as is. Your trading very reliable direct storage for an unreliable software layer which makes the two drives appear as one.

 

[Nermal]

I wonder whether you could do it the old manual way. These instructions will format it using HFS+, but presumably it'll automatically change to APFS when you install the OS.

 

[eccentricglow]

I wonder whether you could do it the old manual way. These instructions will format it using HFS+, but presumably it'll automatically change to APFS when you install the OS.

Unfortunately, I tried doing it the old, manual way and the diskutil commands are missing (or I wasn't seeing them on the list) when accessing the commands. All I could see was resetFusion, and not the create command. I'm guessing unless booting into an older recovery installer (probably sierra or high sierra??)with these commands, doing it the old way is out.

You should reconsider creating a Fusion Drive

Yep, I did reconsider and decided to go without Fusion. I wanted to create a Fusion Drive because I wanted faster speeds to the hard drive that was installed since I was backing up to a SATA SSD before. All in all, I think it worked out because if the backup drive decides to kick the bucket, I can still use the SSD. And if the SSD kicks the bucket -- I have a volume backup on the hard drive. Thanks for confirming that I didn't need to use Fusion after all.