A little over a year ago, I blogged about the TarDisk – a small flash-storage device that promised to add to the storage on your Mac device. Since my MacBook Air only has 128 GB of storage, I picked up a 128 GB TarDisk and got it installed. It doubled my storage space, and seemed like a great investment (even if the re-Pearing process was an absolute nightmare).
Unfortunately, not all that glitters is gold. A year later, and I’m sad to say that I’m no longer using the TarDisk with my MacBook Air. Which means I’m back down to 128 GB of SSD space. However, I also have a functioning laptop, so I’ll take it as a win.
Wait… What about a functioning computer?
It’s important to understand that the TarDisk is essentially a small SD card that, using a built-in macOS function, melds with your internal storage to create something called a “Fusion Drive”. Classically, Fusion Drives are used for computers with regular ol’ hard drives. You get a small solid state and merge it with your internal storage so that you get the speed of a SSD without having to shell out big bucks for an SSD-powered machine.
Essentially, you use software to “fuse” a faster drive to a slower drive. Hence, a Fusion Drive!
I don’t know if Apple intended people to use Fusion Drives to expand their storage. I think it was always done for speed. Regardless, in macOS High Sierra, Apple introduced something called APFS (Apple File System). APFS is a new way your computer stores/manages your files – it’s built to be more secure and efficient. But APFS doesn’t support Fusion Drives.
I was able to update my MacBook Air to High Sierra without any real issues. But last week, when I decided to finally update it to macOS Mojave, I got stuck. I got an error that it couldn’t be installed, and spent several hours with my laptop stuck in a boot loop. Thanks to Google, I knew the error I was getting was tied to the Fusion Drive, but I really didn’t want to format my computer. But no matter what I tried, I couldn’t get my computer to boot normally. I couldn’t even get into Safe Mode.
So the TarDisk had to go. 😵
Un-fusing a Fusion Drive is tricky. It involves completely wiping your machine, un-fusing the drives, and then re-installing macOS. You have to use the Terminal, and if you only have one machine, you better pray your data is backed up. Fortunately, I primarily use my iMac for work now, and everything is backed up to iCloud, so there really wasn’t any risk of losing my data by formatting my laptop. But since I was stuck in a boot loop, I had to boot into internet recovery and do everything there.
When I was done un-fusing the drive, I was left with two devices – my internal SSD and the TarDisk. I was able to re-install macOS to my internal SDD, and BOOM 💥 – working computer.
It’s not really the TarDisk’s fault
When it worked, the TarDisk worked really well. It was a damn near seamless way to increase the storage on my MacBook Air. But it relies on technology that Apple is phasing out and no longer supporting with newer versions of macOS, which makes it risky. I can’t imagine what I would have done if I didn’t have my data backed up to another computer. Updating macOS with the TarDisk means there’s a real chance for significant data loss.
It’s not a risk I’d be willing to take again. Which is unfortunate, because the TarDisk was a really cool little piece of tech. But now, I just have a fancy, seamless, 128 GB SD card. ☹️
Have you ever been excited about a piece of tech that turned out to be a bust? Let me know in the comments!
Thanks soooooooooooooooo much for publishing this how to. I was stuck in a days-long heartbreaking loop trying to Unpear my Tar Disk and reformat my SDD. Yours was the one tutorial that delivered. You save me $2,000! Bless you!
I have been banging my head for years trying to figure out why my MacBook would act weird and not take updates. I was just about to buy a new computer when I found your article. I removed theTarDisk and reformatted. Everything now works with the latest OS. It is like having a new computer again. Since everything is in the cloud, I don’t even need the extra storage. THANKS!