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I have a disk that won't mount

machenryr

machenryr

macrumors 6502a
Original poster
I had to pull out my trusty Disk Warrior and update it to the latest - 5.3.2. I was sure that would fix it but no. It says "Directory cannot be rebuilt because it uses an unsupported version of APFS." OK. Is there another solution. It's a 4TB almost full disk. A lot has been backed up but my backup system I allowed to fall out. This is my second warning. This is an external disk. Any ideas and help would be very much appreciated!
 
What Mac do you have?
What year was it made?
What version of the OS is running?

What is the format of the problem drive?
Has it been partitioned, or anything along that line?
Have you tried mounting it on a DIFFERENT Mac?

If it was used for backups, what backup utility did you use?
 
Fishrrman said:
What Mac do you have?
What year was it made?
What version of the OS is running?

What is the format of the problem drive?
Has it been partitioned, or anything along that line?
Have you tried mounting it on a DIFFERENT Mac?

If it was used for backups, what backup utility did you use?
Click to expand...
Thank you. It's all in my signature. 2025 Mac Studio M4 Max. Sequoia 15.7.7. APFS. Nothing has been partitioned. I have not tried on a different Mac. Thanks
 
The other thing is this SSD, Toshiba 4TB, was purchased last year in January 2025. It's not that old. Everything is new. Although too old for a warranty.
 
Disk Warrior is unable to work with any version of an APFS drive. Have you tried repairing the disk while you are booted into recovery mode?
 
DLary said:
Disk Warrior is unable to work with any version of an APFS drive. Have you tried repairing the disk while you are booted into recovery mode?
Click to expand...
Thank you. No I haven't. In lieu of that is there any other recovery app that I can try?
 
"In lieu of that is there any other recovery app that I can try?"

I could be wrong, but since Apple keeps "the inner workings" of APFS under wraps, I don't think there is ANY 3rd-party software that can actually "repair" APFS drives.

Again, I could be wrong, and I welcome correction from others.

This Toshiba drive...
Did you buy it as a "bare" drive, and then put it into an enclosure?
If possible, have you tried the drive in a DIFFERENT enclosure, or perhaps in a USB3/SATA docking station?
 
Fishrrman said:
"In lieu of that is there any other recovery app that I can try?"

I could be wrong, but since Apple keeps "the inner workings" of APFS under wraps, I don't think there is ANY 3rd-party software that can actually "repair" APFS drives.

Again, I could be wrong, and I welcome correction from others.

This Toshiba drive...
Did you buy it as a "bare" drive, and then put it into an enclosure?
If possible, have you tried the drive in a DIFFERENT enclosure, or perhaps in a USB3/SATA docking station?
Click to expand...
I wish I knew this about APFS. I always take a minute to decide which format to use. I used to get OWC enclosures but this is a 4TB external, no enclosure.
 
The good news is that APFS has much less directory or other structural issues to fix.

The bad news is...there are no good tools outside of Disk Utiliy (that I am aware of) to help should the need arise.

If DU can't fix a drive, I would assume a hardware problem, and would want to immediaetly work on data recovery if needed, and then format the drive and test test test before using to store anything import.
 
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machenryr said:
I wish I knew this about APFS. I always take a minute to decide which format to use. I used to get OWC enclosures but this is a 4TB external, no enclosure.
Click to expand...
It is involved...but interesting info here to know the difference. Note the links to lots more APFS details towards the bottom of the page. Lot's of deeper dive comments on these pages too.
 
machenryr said:
Duh. Meaning I used to buy enclosures from OWC and install the drives myself. These are ready made. Just a little small box with USB connection.
Click to expand...
I second that suggestion to try that drive in a different encolure. They are not all equal. One alternative is a cheap Orico case available on Amazon. I have 2 such cases for 2.5" SSDs, but they also make cheap cases for M2 blades.
All USB enclosures for external SSDs have 2 things in common, a physical case or box to mount the SSD securely and a USB port (normally USB-C or USB-A), but they all have firmware that handles the data transmission, and that can vary from company to company.
The Orical cases are cheap, but they work well, so in this case they are a good choice for a second alternative case.
www.amazon.com

ORICO 2.5'' External Hard Drive Enclosure USB 3.0 to SATA III Tool-Free Clear Hard Disk Case for 2.5 inch 7mm 9.5mm SATA HDD SSD Max 6TB Support UASP(2139U3)

Wide Compatibility - This ORICO SATA hdd enclosure helps to connect your 2.5inch SATA I/II/III hard drive SSD to PC, Laptop, TV and PS4. The hard drive enclosure is suitable for 2.5 inch 7mm/9.5mm 4TB SSD hard drives, and is compatible with Windows, LINUX and Mac OS and above systems.
www.amazon.com
Then once you get access to the drive: In macOS Yosemite or later: the terminal code below will enable TRIM, which notifies the computer's OS that a file space has been deleted, speeding up any subsequent writes to that area and keeping the disk write speeds healthy.

Code:
sudo trimforce enable

USB devices will normally not have TRIM enabled, as it is only supported on a drive connected to a Thunderbolt port or an internal drive.

However, if the UASP protocol is supported on the USB device, TRIM will work. The Crucial MX500 series has this UASP protocol enabled.
To check if UASP is enabled on a currently connected USB devices, use the following command using the Terminal;

Code:
ioreg | grep UAS

If that doesn't show anything, try the following procedure.

Connect the USB device, reboot with the device connected, then use the following code in Terminal; Note: this command can take 15 seconds or more on a 512GB SSD.

Code:
log show --predicate "processID == 0" | grep spaceman | grep -i trim
or
log show --debug --last boot --predicate "processID == 0" | grep trim
log show --debug --last boot --predicate "processID == 0" | grep -e "blocks free in" -e "blocks trimmed"

All of the commands above show Trim is enabled on the Crucial MX500 SSD in a cheap Oraco clear plastic USB 3.1 enclosure.
 
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Before touching more repair software, try to mount it read-only from Terminal. Drives that fail a normal mount often come up read-only, and if they do you can pull the important stuff off before touching anything else. Run diskutil list to find the container (something like disk4), then diskutil apfs mount readOnly disk4s1 (adjust the s number for the actual volume). Even if that errors, diskutil apfs list will tell you whether the container is being read at all, which is a useful diagnostic on its own.

On the sealed-portable side: those ready-made Toshiba boxes usually pop apart with a plastic pry tool along the seam. Inside is a standard M.2 or 2.5" SATA SSD plus a USB bridge chip, and the bridge in a lot of them (ASM235CM or JMS578) has UASP timing issues on Apple Silicon under Sequoia — mounts once, then errors out until the bridge gets power-cycled. Moving the bare SSD into a cheap Orico or Sabrent enclosure often shows the drive itself is fine and the bridge was the failure.

If you need software beyond Disk Utility, DiskGenius (formerly PartitionGuru) actually understands modern APFS containers that Disk Warrior can't touch. Free tier is enough to browse and confirm the file tree is intact, paid tier to actually pull files off.
 
benholt said:
Before touching more repair software, try to mount it read-only from Terminal. Drives that fail a normal mount often come up read-only, and if they do you can pull the important stuff off before touching anything else. Run diskutil list to find the container (something like disk4), then diskutil apfs mount readOnly disk4s1 (adjust the s number for the actual volume). Even if that errors, diskutil apfs list will tell you whether the container is being read at all, which is a useful diagnostic on its own.

On the sealed-portable side: those ready-made Toshiba boxes usually pop apart with a plastic pry tool along the seam. Inside is a standard M.2 or 2.5" SATA SSD plus a USB bridge chip, and the bridge in a lot of them (ASM235CM or JMS578) has UASP timing issues on Apple Silicon under Sequoia — mounts once, then errors out until the bridge gets power-cycled. Moving the bare SSD into a cheap Orico or Sabrent enclosure often shows the drive itself is fine and the bridge was the failure.

If you need software beyond Disk Utility, DiskGenius (formerly PartitionGuru) actually understands modern APFS containers that Disk Warrior can't touch. Free tier is enough to browse and confirm the file tree is intact, paid tier to actually pull files off.
Click to expand...
After reading your post, I tried to download the free version of DiskGenius but the download is obviously a Windows edition, an exe file. Can't find the Mac version on that site.
 
LeVan said:
After reading your post, I tried to download the free version of DiskGenius but the download is obviously a Windows edition, an exe file. Can't find the Mac version on that site.
Click to expand...
There is no Mac version. It's a Windows only app. If you want to use it, you'll need something like VMware Fusion (I use it all the time in VMware on my Mac to clone Windows drives).
 
If you need a data recovery tool to run from/on Macs...I have had good luck with Disk Drill, although I have not used it in a couple years. Free version will show what is on the drive, last I used it. Bonus points: the free version does have some useful tools bundled with it, including showing free space, and a backup/clone tool.
 
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If the OP is still getting nowhere with the drive, then I reckon he has these choices:
1. pry it open, remove the drive from the existing enclosure, and try another enclosure or a USB/SATA docking station
2. start looking for a replacement.

Before completely giving up on it, I'd try connecting it to a different Mac first. No change? Then, try to open the enclosure and put it into a dock*. No change? Time to shop for a replacement.
* Some "ready to use" SSDs come in non-openable enclosures, such as my Samsung "T7 Shield" and Crucial X9. Without seeing a pic of the OP's drive, can't tell.

From experience, I've found that when SSDs fail, they often just "go dark" on you -- no warning, they don't show up anywhere, just... gone. Poof! Like that...
It is, what it is.
 
I've had a very similar issue with an NVME SSD inside an external enclosure with an M5 MBA running Golden Gate. However, if I connected the enclosure with an USB hub in between, it worked. And it also works if I connect it to another mac running Sequoia.

As far as I could investigate, the problem is related to the bridge controller and maybe the USB stack in macOS GG. I have posted my findings here:
forums.macrumors.com

DevBeta 3: External USB NVMe enclosure detected but block device is not created (Apple Silicon)

I have one dock with two HDDs, and one SSD inside a USB 3.2 enclosure but none of this external drives will show up in Finder, neither would be listed on Disk Utility, when I plug them in. The same devices work correctly on macOS 15.7.7 on an Intel based MacBook Pro, but they don't on macOS 27...
forums.macrumors.com forums.macrumors.com

I've also created a ticket in Feedback Assistant with code FB23717221. It was my first time sending something like this and used a lot of ChatGPT to create the report.
 
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