An external disk refuses to mount, com.apple.DiskManagement.disenter error -119930868.

You do so how ridiculous that is though, right? If I'm on a project and I need access to files at that exact moment from a hard drive, with your solution, I'd have to wait overnight before I can access the files? That's just NOT ACCEPTABLE. EVER. Not in any work environment I know of.

I'm going to try leaving it in overnight, but at this point I think my next computer is going to be a Dell. I can't believe that Apple is just ignoring this problem.

Unfortunately the fsck process does not seem to work for me as I cannot locate this function in the Activity Monitor.

So here is my rendition of the "My drive won't mount on Catalina and..." posts that have stacked up nicely in this thread.

So I'm running a 12 tb 4 bay media sonic raid 5 to back up video and photo work. I backed up my back up to a JBOD earlier in the week and all was well. Then I decided to shuffle some media around, end goal being to move a few things back onto 12tb array. Decent amount of files, I'd say like around 1.5 tb. So I set it forget it and let it do it's thing overnight. When I check in the morning my system is frozen. The transfer errored out and I panic, instinctively tapping the caps lock button hoping to see the green light blink on then off. The only vital sign I can check before doing the much dreaded hard shut down. I do the hard shutdown, fire it back up and the array will not mount. I tried the whole Kill the "FSCK" in activity monitor, this did not work. I've also heard rumors on here of people hooking the "unmountable drive" up to a system running a different OSX. I am running a dual boot with Catalina on one volume and Mojave 10.14.6 on another. I am currently typing this post from Safari on the Mojave volume as I stare blankly at disk manager and the greyed out drive (array) which is yet to mount.. I supposed I will "give it time" which was also mentioned in this monumental thread which has yet to be addressed by anyone from apple. I'll check back here in a few days with an update but if you're any where near as optimistic as I am for a fix on this, you won't hold your breath.

Nothing wrong with holding your breath & waiting. That’s all you can do for now.

Has happened to me a number of times when on boot up, the HDs were not seen on the desktop. Tried all sorts of remedies. Nothing worked. Resigned to fate !

Mysteriously, after some time, up to an hour or two, or even the next day, the HDs reappear.

Happened both in High Sierra & Catalina.

I have no idea what happened.

Have faith. Good luck !

Update on my previous post. I left the drive in for 72 hours and it still did not mount. I have also never seen the fsck process appear in the Activity Monitor. The most recent Catalina update has also not fixed the issue.

This is beyond ridiculous.

Apple, why will you not at least tell us you are working on a fix?

I am on an early 2015 Macbook Pro.

So here I am again, a couple months after my original reply in this thread. Raid still won't mount. I found and tried all this stuff. Can confirm this does not work either. It's a bunch of terminal commands to mount and unmount drives. Terminal said the process timed out. I did it a bunch of times.

https://osxdaily.com/2013/05/13/mount-unmount-drives-from-the-command-line-in-mac-os-x/#comments

I am having the same issue/error code HOWEVER, I just recently updated my IOS to Big Sur to see if this would solve the issue and not only it isn't mounting, it is also corrupting my expensive Memory Cards! I am being as careful as possible but seems like it's just not mounting ANY of my cards and only a few smaller memory cards under 128GB seem to be able to mount after trying a few times. I am a photographer and the thought of images being lost is a total nightmare.... my current laggy fix is to use my Mark IV wi-fi feature to teadiously transfer them... HELP PLEASE!!!

Do You have an iPad/iPhone? Do you have or use Adobe Lightroom cloud ? You could get the SD to lightning card reader and ingest your photos that way. I do this when I’m away and wanna edit remotely. It works flawlessly. Lightroom cloud detects an external media source is connected. It will suck the photos right into LR and up them to your cloud. From there you could pull them down vis desktop.

@Starburns we shouldn't have to look for alternative solutions to get assets off of external drives. It's insane. @Apple needs to respond to this thread. There's 13 pages of 'try this' and 'try that', most of which fail. I work with video files that are on multiple drives and I need to swap out drives daily. I should just be able to plug in the hard drive and bam, there it is on my desktop and ready to use.

I have this exact same issue, but this time after I installed "Big Sur" OSX update earlier today.

For ages I've had a 1TB external drive, partitioned into two parts, one part for use by Time Machine, the other part for use as Drag and Drop. The drag and drop partition mounts fine. After the Big Sur upgrade the Time Machine part will not mount and disk utility gives this error:

"com.apple.DiskManagement.disenter error 0."

It is now several hours since I did the upgrade. The Drag and Drop partition mounts fine, so it cannot be anything to do with the physical disk.

Is the Time Machine part doing some kind of housekeeping? It seems to be rumbling a bit from time to time, and it rumbles when I try to mount it via DIsk Utility, but then it gives the error message: "com.apple.DiskManagement.disenter error 0."

I understand that I could reformat the disk to get Big Sur to work on it better. But I cannot do anything if it doesn't mount.

Should I just wait?

I have a WS Passport 1TB that macOS won't mount my Time Machine volume; Disk Utility reports

Could not mount “Time Machine”. (com.apple.DiskManagement.disenter error -119930872.)

I'm on a MBP running Catalina 10. I 15.7. I rebooted and it still won't mount.

I tried to reformat it but that also fails trying to mount; first aid also fails (disenter error -119930872 again; see screen shot attachment)

This external disk mounts fine on a different Big Sur MBP.

Just had the same problem when updating to Catalina 10.15.7 (19H114). Tried killing the fsck_exfat in my case and that gave me an error message saying Can't repair my drive and I can still read and save but not save while open a file. I think it's still the same issue, when updating it triggers the fsck. Anyone from apple on this?

I have an external drive with one data partition and one Time Machine partition. Worked fine until December, then I could not mount either of them with this error. I can mount them on another MBP running Big Sur. I also upgraded this MBP to Big Sur and was able to mount them, but had to downgrade back to Catalina for other software incompatibilities, and now I cannot mount the Time Machine disk again. Sigh.

FYI - My disk got erroneously ejected again and this time I watched how long it took to become available after reboot. It took roughly 40 minutes for a 4TB Seagate disk to be mounted on my 2019 16" MacBookPro.

I am really very grateful to you, you have helped me save a very valuable information about my work and personal projects. I do not know how to thank you. Greetings from Mexico, blessings and good vibes.