Mac mini SSD Not mounting

[Marco Rookie]

My 1TB external SSD is not mounting after a power interruption or reboot. The Mini doesn't see it with Disk Utility, and I have to physically unplug & replug the drive to get the Mini to recognize it.
SSD Western Digital 1TB SN850X M.2 2280 Black 3D
Qwiizlab Fanless 40Gbps USB4 Thunderbolt External SSD (enclosure)
Mac mini m4
16GB memory
Sequoia 15.3.1 (it's a brand new mini, always the same behaviour in previous versions of sequoia)
apfs formated ssd
does anyone know how to fix it?

 

[Patrice Brousseau]

My 1TB external SSD is not mounting after a power interruption or reboot. The Mini doesn't see it with Disk Utility, and I have to physically unplug & replug the drive to get the Mini to recognize it.
SSD Western Digital 1TB SN850X M.2 2280 Black 3D
Qwiizlab Fanless 40Gbps USB4 Thunderbolt External SSD (enclosure)
Mac mini m4
16GB memory
Sequoia 15.3.1 (it's a brand new mini, always the same behaviour in previous versions of sequoia)
apfs formated ssd
does anyone know how to fix it?

Could you try the NVMe in another computer to rule out a dead SSD? Same goes for trying a spare NVMe in the enclosure to rule out a failed enclosure?

Something else USB-C or Thunderbolt to verify that the port still works correctly?

PRAM or NVRAM and SMC reset done (is it still a thing with M chips?)?

Personnaly, I use a TB enclosure (Acasis) with a little fan to prevent NVMe overheat.

 

[Marco Rookie]

I've tried in my old imac, works fine. the curious thing is the light is white in the enclosure (i think that's because it's connected to a normal usb port.
In mac mini, normally i connect to thunderbolt ports so the light is green. that's a good idea, i have to try it in a normal usb-c port on mac mini. i give you the feedback later, thanks for helping.

 

[Marco Rookie]

I've tried in my old imac, works fine. the curious thing is the light is white in the enclosure (i think that's because it's connected to a normal usb port.
In mac mini, normally i connect to thunderbolt ports so the light is green. that's a good idea, i have to try it in a normal usb-c port on mac mini. i give you the feedback later, thanks for helping.

if i connect via a normal usbc port it takes a lot to charge... i dont know why.
The thing is... i did already a smc reset, but all the same.

In System information i can see the device connected on thunderbolt usb4, the only problem is, doesnt mount himself. iHave to unplugged and plug again the cable:

Thunderbolt/USB4 Bus 0:

Vendor Name: Apple Inc.
Device Name: Mac mini
UID: 0x05AC278AF54B4680
Route String: 0
Domain UUID: 0CC866A8-27DC-4E55-ABCE-F0B9A2DBDDE8
Port:
Status: Device connected
Link Status: 0x2
Speed: 40 Gb/s
Receptacle: 1

246x:

Vendor Name: ASMedia
Device Name: 246x
Mode: USB4
Device ID: 0x2463
Vendor ID: 0x174C
Device Revision: 0x5A
UID: 0x174C4C15289AC460
Route String: 1
Firmware Version: 47.3
Port (Upstream):
Status: Device connected
Link Status: 0x2
Speed: 40 Gb/s

 

[Patrice Brousseau]

if i connect via a normal usbc port it takes a lot to charge... i dont know why.
The thing is... i did already a smc reset, but all the same.

In System information i can see the device connected on thunderbolt usb4, the only problem is, doesnt mount himself. iHave to unplugged and plug again the cable:

Thunderbolt/USB4 Bus 0:

Vendor Name: Apple Inc.
Device Name: Mac mini
UID: 0x05AC278AF54B4680
Route String: 0
Domain UUID: 0CC866A8-27DC-4E55-ABCE-F0B9A2DBDDE8
Port:
Status: Device connected
Link Status: 0x2
Speed: 40 Gb/s
Receptacle: 1

246x:

Vendor Name: ASMedia
Device Name: 246x
Mode: USB4
Device ID: 0x2463
Vendor ID: 0x174C
Device Revision: 0x5A
UID: 0x174C4C15289AC460
Route String: 1
Firmware Version: 47.3
Port (Upstream):
Status: Device connected
Link Status: 0x2
Speed: 40 Gb/s

Hardware incompatibility with M chips Macs?

 

[bzgnyc2]

if i connect via a normal usbc port it takes a lot to charge... i dont know why.

I am not quite sure what you mean here.

The thing is... i did already a smc reset, but all the same.

Note Apple Silicon doesn't have a keyboard reset. Your options along these lines are:

-Power off computer wait 30 seconds and turn back on

-Power on first holding power button:

Mac startup key combinations - Apple Support

Learn about the Mac features and tools that you can access by holding down one or more keys during startup.

support.apple.com

-Power on into Options:

If your Mac starts up to Options with a gear icon - Apple Support

The startup options window shows icons for each available startup disk, a gear icon labeled Options, and buttons for Shut Down and Restart.

support.apple.com

-Power on into Safe mode (which will clear all system and kernel cache which will then be rebuilt on normal next boot);

Start up your Mac in safe mode - Apple Support

To help determine whether an issue is caused by software that loads as your Mac starts up, you can start up your Mac in safe mode.

support.apple.com

In System information i can see the device connected on thunderbolt usb4, the only problem is, doesnt mount himself. iHave to unplugged and plug again the cable:

Thunderbolt/USB4 Bus 0:
...

This is helpful as it confirms at least the system sees the devce.

If none of the above helps, few things to try to check and share to help us figure out what's going on:
-After the system boots with the device connected but not visible by the system,
*Is the device visible at all in Disk Utility if you go to View-> Show All Devices
*In System Information, does the drive show up under NVMExpress as well as Thunderbolt/USB4?
*If not, can you grab screenshots of USB, Thunderbolt/USB4, NVMExpress, Storage as a snapshot in the non-working state and then grab the same after you unplug and plug the drive?

-One more thing, when in the Disk Utility from the Recovery Mode (e.g. after booting into Options above), is the drive visible and does it show up the same way as when seen from Disk Utility in regular macOS?

P.S.I am assuming you already did First Aid from Disk Utility on the entire device since this first started.

 

[Marco Rookie]

I am not quite sure what you mean here.

sorry, i'm portuguese, my english is not so good. what i was trying to say is that it takes a lot of time to mount if i connect in a normal Usbc Port (not thunderbolt)

 

[Marco Rookie]

This is helpful as it confirms at least the system sees the devce.

If none of the above helps, few things to try to check and share to help us figure out what's going on:
-After the system boots with the device connected but not visible by the system,
*Is the device visible at all in Disk Utility if you go to View-> Show All Devices - NO
*In System Information, does the drive show up under NVMExpress as well as Thunderbolt/USB4?- YES
*If not, can you grab screenshots of USB, Thunderbolt/USB4, NVMExpress, Storage as a snapshot in the non-working state and then grab the same after you unplug and plug the drive?

Note Apple Silicon doesn't have a keyboard reset. Your options along these lines are:

-Power off computer wait 30 seconds and turn back on

-Power on first holding power button:

Mac startup key combinations - Apple Support

Learn about the Mac features and tools that you can access by holding down one or more keys during startup.

support.apple.com

-Power on into Options:

If your Mac starts up to Options with a gear icon - Apple Support

The startup options window shows icons for each available startup disk, a gear icon labeled Options, and buttons for Shut Down and Restart.

support.apple.com

-Power on into Safe mode (which will clear all system and kernel cache which will then be rebuilt on normal next boot);

Start up your Mac in safe mode - Apple Support

To help determine whether an issue is caused by software that loads as your Mac starts up, you can start up your Mac in safe mode.

support.apple.com

i will try this tonight, thank you in advance.

 

[bzgnyc2]

it takes lot of time to mount if i connect in a normal Usbc Port (not thunderbolt)

Okay this is helpful and another clue that something is off. Simply mounting a properly working SSD with a consistent partition map/filesystem/etc should take about the same whether Thunderbolt or USB 3+ (i.e ~ 1 second or less).

You might keep the Console open while you connect the drive via USB and/or monitor log files (/var/log/system.log, /var/log/fsck_apfs.log, etc) and/or use the Terminal command "log show" (the previous more appropriate if you don't frequently work at the UNIX command-line) to see what it is doing.

If none of the above helps, few things to try to check and share to help us figure out what's going on:
-After the system boots with the device connected but not visible by the system,
*Is the device visible at all in Disk Utility if you go to View-> Show All Devices - NO
*In System Information, does the drive show up under NVMExpress as well as Thunderbolt/USB4?- YES
*If not, can you grab screenshots of USB, Thunderbolt/USB4, NVMExpress, Storage as a snapshot in the non-working state and then grab the same after you unplug and plug the drive?

i will try this tonight, thank you in advance.

Curious if any of those resets worked? Or if you are still having problems can you share the screenshots/copies of those sections of System Information? I haven't seen something show up under Thunderbolt, NVMExpress, and Storage but not Disk Utility at least a Device. You might also see if the results of the Terminal command "diskutil list" matches what Disk Utility shows.

 

[Marco Rookie]

Curious if any of those resets worked? Or if you are still having problems can you share the screenshots/copies of those sections of System Information? I haven't seen something show up under Thunderbolt, NVMExpress, and Storage but not Disk Utility at least a Device. You might also see if the results of the Terminal command "diskutil list" matches what Disk Utility shows.

the resets didnt work...

here's some screenshots from disk utility and system information (thunderbolt port) thank you for helping

 

[Daydog]

Check you haven't got it plugged into the DFU port.because on the Mac Studio Thunderbolt Bus 0 is DFU port
and if it is you will get nothing but problems with HD Disks connected..

 

[bzgnyc2]

the resets didnt work...

here's some screenshots from disk utility and system information (thunderbolt port) thank you for helping

Just to confirm -- these are from the initial boot when the drive is connected but not mounting the filesystems on the drive? Would be good to also repeat the same after you unplug and plug. Also curious the contents of the NVMExpress and USB trees of System Information.

Based on your screenshots, the system sees the enclosure and is establishing a bridge though it to access the Samsung via NVMe as if it is on the PCI bus. That's good though there is the oddity of the slow link speed shown under PCI. Then definitely not showing up under Stroage. The gap in the chain would seem to be in NVMExpress so would be good to see the screenshots from it as above. Then I'd be curious if when you unplug and plug back in and how all these look (plus the USB tree before and after).

Though too soon to tell I'm leaning towards an Thunderbolt/USB4 cable or enclosure failure that was just conincidental with your power failure.

Also, no harm either in trying it in a different slot as another poster mentioned.

 

[Marco Rookie]

Just to confirm -- these are from the initial boot when the drive is connected but not mounting the filesystems on the drive? Would be good to also repeat the same after you unplug and plug. Also curious the contents of the NVMExpress and USB trees of System Information.

repeating with the unplugg and plug again.... "This SShots are with the SSD working perfectly"

 

[bzgnyc2]

repeating with the unplugg and plug again.... "This SShots are with the SSD working perfectly"

I am not quite sure it's perfect. It looks like it is connecting via USB 3.1 even though I understand you are connecting to the same Thunderbolt 4/USB4 port on the back?

View attachment 2484348

View attachment 2484352

One thing on these last screenshots it would have been helpful to click on the drive -- so "MMHD" in the first one above and "ASM246X series" in the last one. Otherwise it doesn't show the details specific to the drive. However, I think we know what it will say -- that it is connecting the drive via USB protocols and link speed 10Gbit rather than PCI-Express protocols and link speeds 40Gbit.

The one screenshot still missing is the "NVMExpress" tree right after the initial boot (i.e. when it's showing up under PCI but not under Storage). That's where the gap is between seeing the enclosure and drive on the PCI bus and nothing showing up in Storage. Not sure at this point it will give us insight but by chance it might.

In the meantime, just to confirm:
-If you unmount/eject, unplug, wait 30 seconds, and replug in the back, does it ever show up again under the Thunderbolt/USB4 tree?
-If not, do you get different results when you do the same in either of the other two rear ports?
-If you boot with it connected in the front, does automatically mount?
-Also you mentioned that it takes a long time to mount if you plug it into a USB-C port -- was that front? Is the time to mount the same with the front USB-C ports as when you unplug and plug it into the rear ports?
-What is the exact model of your old iMac? iMac models 2017 or later (iMac18,1+) had Thunderbolt3 ports. If your iMac has Thunderbolt 3, does this enclosure show up under the Thunderbolt tree of System Information when you plug it into one of its Thunderbolt 3 ports?
-Can you easily acquire or know someone who can lend you a high-quality passive Thunderbolt 4 cable? Intel-ceritified and in the 70-80cm range.

 

[Marco Rookie]

i changed the rear port and i send you some prints (after unplug, wait 30 seconds and plug again)

n the meantime, just to confirm:
-If you unmount/eject, unplug, wait 30 seconds, and replug in the back, does it ever show up again under the Thunderbolt/USB4 tree? (yes)
-If not, do you get different results when you do the same in either of the other two rear ports?
-If you boot with it connected in the front, does automatically mount? ( i will try next and i tell you)
-Also you mentioned that it takes a long time to mount if you plug it into a USB-C port -- was that front? (yes the front)Is the time to mount the same with the front USB-C ports as when you unplug and plug it into the rear ports?
-What is the exact model of your old iMac? imac 27 inch late 2013 iMac models 2017 or later (iMac18,1+) had Thunderbolt3 ports. If your iMac has Thunderbolt 3, does this enclosure show up under the Thunderbolt tree of System Information when you plug it into one of its Thunderbolt 3 ports?
-Can you easily acquire or know someone who can lend you a high-quality passive Thunderbolt 4 cable? Intel-ceritified and in the 70-80cm range. (i have to buy it... i will try too this weekend)

 

[bzgnyc2]

i changed the rear port and i send you some prints (after unplug, wait 30 seconds and plug again)

Just to summarize and validate the situation/data points we have across the postings:
-Booting with drive connected to rear port 0, the SSD drive is visible on PCI bus but system does not present filesystem(s) (not visible under 'Storage', unclear 'NVMExpress')
-Unplugging and replugging in a front USB-C, enclosure/SSD drive is visible as a USB storage device and mounts filesystem, etc (though it takes a relatively long time)
-Unplugging and quickly replugging in to rear port 0, enclosure/SSD drive shows up a a USB device similar to having been plugged into front USB-C?
-Unplugging from port 0 and waiting 30 seconds, and plugging in to rear port 3, SSD drive is visible as an NVMExpress device and mounts filesystem as expected?


Besides testing another cable (which is now unlikely the issue assuming that last configuration holds and is reliable), does the system automatically mount the drive properly at boot if connected to rear port 3?

When unplugging and replugging in port 0 and the drive mounts as USB, is there any difference in the time to mount as compared to when plugging into a front USB-C?

Did the drive automatically mount when connected at boot to a front USB-C?

 

[Marco Rookie]

Just to summarize and validate the situation/data points we have across the postings:
-Booting with drive connected to rear port 0, the SSD drive is visible on PCI bus but system does not present filesystem(s) (not visible under 'Storage', unclear 'NVMExpress')
-Unplugging and replugging in a front USB-C, enclosure/SSD drive is visible as a USB storage device and mounts filesystem, etc (though it takes a relatively long time)
-Unplugging and quickly replugging in to rear port 0, enclosure/SSD drive shows up a a USB device similar to having been plugged into front USB-C? (yes)
-Unplugging from port 0 and waiting 30 seconds, and plugging in to rear port 3, SSD drive is visible as an NVMExpress device and mounts filesystem as expected? (yes)


Besides testing another cable (which is now unlikely the issue assuming that last configuration holds and is reliable), does the system automatically mount the drive properly at boot if connected to rear port 3? (i dont have another cable to test it)

When unplugging and replugging in port 0 and the drive mounts as USB, is there any difference in the time to mount as compared to when plugging into a front USB-C? it's fast on rear... and works well after

Did the drive automatically mount when connected at boot to a front USB-C? yes, but it takes some time. i'm trying to boot, and i'm waiting 5 minutes... not mounted until now.

i notice something, even if i tought i was buying a thunderbolt 4 cable, i realized it's a usbc4 cable. maybe it's because of this?

 

[bzgnyc2]

Just to summarize and validate the situation/data points we have across the postings:
-Booting with drive connected to rear port 0, the SSD drive is visible on PCI bus but system does not present filesystem(s) (not visible under 'Storage', unclear 'NVMExpress')
-Unplugging and replugging in a front USB-C, enclosure/SSD drive is visible as a USB storage device and mounts filesystem, etc (though it takes a relatively long time)
-Unplugging and quickly replugging in to rear port 0, enclosure/SSD drive shows up a a USB device similar to having been plugged into front USB-C? (yes)
-Unplugging from port 0 and waiting 30 seconds, and plugging in to rear port 3, SSD drive is visible as an NVMExpress device and mounts filesystem as expected? (yes)


Besides testing another cable (which is now unlikely the issue assuming that last configuration holds and is reliable), does the system automatically mount the drive properly at boot if connected to rear port 3? (i dont have another cable to test it)

When unplugging and replugging in port 0 and the drive mounts as USB, is there any difference in the time to mount as compared to when plugging into a front USB-C? it's fast on rear... and works well after

Did the drive automatically mount when connected at boot to a front USB-C? yes, but it takes some time. i'm trying to boot, and i'm waiting 5 minutes... not mounted until now.

I don't have an explanation for why this drive would mount dramatically slower when connected to the front USB-C ports than the rear USB4/TB4 ports. Peak transfer rates can be up to 2-4x faster over USB4/TB4 than USB 3.x 10Gbit but that shouldn't be an issue for mounting.

For now let's assume the issue has to be one of these 4 things:
-NVMe SSD
-USB4/NVMe enclosure
-USB4 cable
-Mac Mini rear USB4/TB4 port 0

Then we have these data points:
1. Mac Mini M4 rear USB4 port 0 (assuming leftmost), connected at boot: tries to connect at USB4/NVMExpress and then fails (more details about this may be under the NVMExpress tree of System Information)
2. Mac Mini M4 rear USB4 port 0, unplugged and replugged after boot: works fine except at USB3.x (lower peak speed and other limitations plus annoying to have to unplug and replug)
3. Mac Mini M4 rear USB4 port 3 (assuming rightmost), unplugged and replugged after boot: connects at USB4/NVMExpress and works fine (unclear if same result when connected this way before boot)
4. Mac Mini M4 front USB3.x 10Gbit: takes a long time to mount but then performs well (of course lower peak speed and other limitations)
5. Mac 2013 USB 5Gbit: performs well but of course at 5Gbit

Given cases #2, #3, and #5, it seems unlikely the NVMe SSD, enclosure, or cable. Though given #1 and #4, I am less certain about the enclosure and cable. Plus I can't explain the long time to mount under #4 but not #2.

For now, I would try booting with the enclosure/SSD connected to rear USB4 port 3 and seeing if it connects to the drive as an USB4/NVMExpress device at boot and automatically mounts, too. If so, I'd say issue #4 is unrelated and the more important issue is that USB4/TB4 port went bad. If the system behaves differently whether the SSD/enclosure is connected to rear port 0 versus rear port 3, I'd return to Apple to fix (likely requiring a new logic/system replacement).

One other weird thing you could try as far as #1, #2, and #4, is plugging the cable into the Mac with the USB-C connector rotated 180 degrees. This should not make a difference in any proper cable/device/etc and should not make a difference with any USB4 device. I've only heard issues with this in case of USB-A <-> USB-C scenarios and so shouldn't make a difference. But given some of your unexplained results and testing this should only takes 10s of seconds, I would just repeat #1 and #4 above with the cable both ways for sanity's sake.

i notice something, even if i tought i was buying a thunderbolt 4 cable, i realized it's a usbc4 cable. maybe it's because of this?

The standards are way too complicated these days but the summary is that a USB4 cable might be of high-quality but it isn't certified to the same level. Whether it works in all USB4 situations depends on the manufacturer. An Intel-certified passive TB4 cable should "always" work for all USB4 and TB4 situations.