Disk Utility won't format external SSD

[sfwalter]

Found a simple workaround for this problem. It was driving me crazy because I have 2 of these 4TB SSD's, and they format fine on Windows. The workaround is simple: simply use a slower USB 2 cable, which for me is simply using the USB-C cable that came with the AC adapter for my MBP (Intel). When I used that cable with the Sandisk Extreme v2, then Disk Utility formatted the drive in about 20 seconds. After it's formatted, then going back to the stock cable immediately returned the speed to normal.

Clearly a bug in Monterey, but the simple workaround did the trick after countless hours trying to wait out Disk Utility.

Hope this helps somebody else...

Thanks! This saved me from having to return the drive. I thought it was defective.

 

[ElectricPotato]

Clearly a bug in Monterey, but the simple workaround did the trick after countless hours trying to wait out Disk Utility.

Hope this helps somebody else...

Many thanks! I wasted hours chasing this problem with a new external 4TB SSD. Both my macs are already Monterey so running Big Sur was not an option for me. The USB2 trick saved the day and my sanity.

This is one of those Apple bugs so severe and obvious that it shakes my faith in their technical abilities. It's regressions on top of regressions these days.

 

[ElectricPotato]

MacOS 12.1 came out and it fixes this bug as far as I can tell. The same 4TB external SSD that had problems on 12.0.1 now formats in seconds on USB 3.

 

[ahaynes42]

Unfortunately for me the 12.1 update did not fix the issue. It still struggles to read and write to this drive that works fine with other systems. Brings the computer to a halt pretty much until I unplug it. Sounds like they fixed some of the SSD controller firmware incompatibility issues for some drives but not all.

 

[ahaynes42]

Well at least one of the companies has officially acknowledged that there is a problem. Too bad they haven't fixed it yet. This is from Western Digital's webiste, who also owns SanDisk and G-Drive.

 

[sfwalter]

Surely this would have been fixed by now in 12.3.1. However, the problem stil persists. Using a slow USB2 cable trick still works.

 

[w5jck]

Update: I tried formatting as exFAT and HFS, didn't work. I plugged it into my wife's MacBook Air, which is still running Big Sur. It erased and formatted as AFPS within 15 seconds. Seems to be a Monterey issue with this drive.

Probably a Monterey issue. Monterey has more bugs than a dead elephant carcass! I has no issue formatting a Samsung T5 2TB SSD to APFS on my MacBook Pro 2014 running Mojave, and it now works fine on my new MacBook Air M1.

 

[EssentialGadget]

Has this been fixed in Monterey 12.4? Does Ventura fix this issue?

 

[kibepo73]

The easiest way to erase any storage drive on Mac is by using Disk Utility feature. But sometimes, Mac Disk Utility can’t erase the storage drive due to various reasons. However, the issue can be fixed using below DIY methods:

1. Erase Mac Hard Drive by Enabling ‘Show All Devices’.
2. Use First Aid to Repair Drive before Erasing.
3. Use Recovery Mode to Erase Storage Drive.
4. Erase Data using BitRaser File Eraser software.

Hope it will help!

 

[Rodan52]

I have two Samsung T5 2TB SSD's both originally formatted via USB - C to USB - A on a 2015 MBP. They also come with Type C to Type C cables which I now use on both my wife's 2018 MBP and my new M1. In all cases I was/am running Monterey including the 2015 MBP. So my guess is it's not Montetey at fault here but the M1 SoC. Meaning a software upgrade may not fix the issue.

 

[Apuk]

Found a simple workaround for this problem. It was driving me crazy because I have 2 of these 4TB SSD's, and they format fine on Windows. The workaround is simple: simply use a slower USB 2 cable, which for me is simply using the USB-C cable that came with the AC adapter for my MBP (Intel). When I used that cable with the Sandisk Extreme v2, then Disk Utility formatted the drive in about 20 seconds. After it's formatted, then going back to the stock cable immediately returned the speed to normal.

Clearly a bug in Monterey, but the simple workaround did the trick after countless hours trying to wait out Disk Utility.

Hope this helps somebody else...

Where do you get the usb 2 cable from?? I couldn't find any usb c to usb 2 cable
Thanks

 

[KennyJr]

I tried as you did. I had the same problem with my Samsung T5 SSD. I found instructions online that said to first format to MacOS Extended - then - format a second time to APFS. That solved the problem for me.

 

[sfwalter]

I tried as you did. I had the same problem with my Samsung T5 SSD. I found instructions online that said to first format to MacOS Extended - then - format a second time to APFS. That solved the problem for me.

I will have to try this next time. Thanks for the tip!

 

[davidlv]

I will have to try this next time. Thanks for the tip!

I had a similar issue trying to format a Buffalo 1TB external disk (not an SSD, a HDD) formatted as macOS Extended, connected to a USB 3.0 port.
Got an error message saying that the process "fseventsd" was preventing the disk from being unmounted.
The solution that worked (found before seeing this thread) was to boot in safe mode.
Then I was able to format the disk as APFS.

 

[EssentialGadget]

I posted earlier about issues where Monterey would not read or format my Samsung 4TB EVO 860 SSD. Big Sur worked perfectly with it but multiple Monterey machines would not. I used it as a boot drive on a 2019 iMac.

I upgraded to a MacStudio with 4TB SSD and it would not read this drive either. Had to migrate from a 5TB HDD.

I finally had some time to experiment some more. I connected the drive to a Monterey 12.4 2019 Intel i9 MBP.
I formatted it to EXFAT GUID Partition. It took at least 30 minutes to an hour. Just let it crank.

It finally completed. Worked fine. I then formatted it APFS GUID Partition. Formatted quickly as expected. Works fine - 500+MB read/write on Blackmagic.

Currently using as a backup drive with MacStudio - no issues.

I will probably rotate all my SSDs and HDDs through this process to make sure they are Monterey compatible. Some of my HDDs seem a little too slow/quirky on Monterey.

Just remember the EXFAT format can take a long time.

NOTE: I used a USB 3.x cable for this.