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TimC00ked

macrumors newbie
Original poster
Aug 11, 2025
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I have the Mac mini m4 connected via TB4 to a OWC express 1m2 enclosure containing a samsung 990 pro ssd and I'm experiencing numerous unsafe shutdowns when the Mac goes to sleep. Around 5-10 a day. The drive doesn't eject/unmount though, so I wouldn't have known there was an issue if it wasn't for the drive's SMART stats. Is my enclosure defective and should I be concerned about these numbers? I'm trying to figure out what I should do. Would it make sense to prevent the Mac from sleeping and is there a way for the Mac to sleep while preventing the ssd from sleeping? I tried using Jettison to eject the drive when the Mac sleeps but I always have apps accessing the drive which prevents ejects. I also tried Amphetamine's drive Alive feature but that only works when the Mac is not sleeping so it's not useful for me.
 
I have the Mac mini m4 connected via TB4 to a OWC express 1m2 enclosure containing a samsung 990 pro ssd and I'm experiencing numerous unsafe shutdowns when the Mac goes to sleep.
Are you using the original 12-inch USB cable that shipped with the enclosure?
 
The usb/thunderbolt power software stack in macos is somewhat finicky and unreliable. Your best bet would be to keep the mini from going to sleep. Energy consumption difference is minimal. The alternative would be a shutdown of the mini, which would be more sustainable anyways of you let your mac sleep during nighttime.

There is no real solution to this at the moment, as Apple needs to improve their drivers.
 
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Same enclosure, same problem, in a Studio. I use Jettison, have for years with MacBooks and externals where I’ve frequently had problems. Excellent tool.
 
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The usb/thunderbolt power software stack in macos is somewhat finicky and unreliable. Your best bet would be to keep the mini from going to sleep. Energy consumption difference is minimal. The alternative would be a shutdown of the mini, which would be more sustainable anyways of you let your mac sleep during nighttime.

There is no real solution to this at the moment, as Apple needs to improve their drivers.

My concern with preventing sleep is that the fan will always be running at 1000 rpm so I don't know if that's good for the Mac in the long term.

Seems like this is a problem that has plagued apple devices for a while so I don't have high hopes of a fix anything soon. :(

Same enclosure, same problem, in a Studio. I use Jettison, have for years with MacBooks and externals where I’ve frequently had problems. Excellent tool.
Do you have app data on the external drive? I have, such as from the Photos app, that prevent me from easily ejecting the drive since there's always a process accessing the drive.
 
My concern with preventing sleep is that the fan will always be running at 1000 rpm so I don't know if that's good for the Mac in the long term.
It's fine, I've had Mac minis running for nearly a decade on 24/7 with the fan running. I stopped shutting them off when I started using them as a media server, it's no big deal.
Seems like this is a problem that has plagued apple devices for a while so I don't have high hopes of a fix anything soon. :(
Indeed, I remember back in 10.12 or 10.13 having issues where closing my MacBook lid for even a second would improperly eject the disk, which ended up corrupting the document that I had open. Maybe Apple is trying to do this for energy efficiency? It doesn't really make sense why they wouldn't at least force eject it first. Certainly doesn't make sense at all on a desktop.
Do you have app data on the external drive? I have, such as from the Photos app, that prevent me from easily ejecting the drive since there's always a process accessing the drive.
Yup, I've seen Jettison and to be honest I don't see the point in it. If I have the drive connect, I have files opened from it, forcibly ejecting it any way will at the very least break the open file handle, meaning I will have to re-open the documents anyways. At worst it will corrupt a document you're editing, and in the middle I see many apps don't take it very well and freeze up when the drive disappears.
 
It's fine, I've had Mac minis running for nearly a decade on 24/7 with the fan running. I stopped shutting them off when I started using them as a media server, it's no big deal.

Indeed, I remember back in 10.12 or 10.13 having issues where closing my MacBook lid for even a second would improperly eject the disk, which ended up corrupting the document that I had open. Maybe Apple is trying to do this for energy efficiency? It doesn't really make sense why they wouldn't at least force eject it first. Certainly doesn't make sense at all on a desktop.

Yup, I've seen Jettison and to be honest I don't see the point in it. If I have the drive connect, I have files opened from it, forcibly ejecting it any way will at the very least break the open file handle, meaning I will have to re-open the documents anyways. At worst it will corrupt a document you're editing, and in the middle I see many apps don't take it very well and freeze up when the drive disappears.

That’s good to hear that your Mac has been running like this for this long without issues. Preventing sleep might even be better for the external drive since it leads to less power cycles although the average temp of the driver will be higher. Mine tends to hover around 45C.

I could understand this if your MacBook was running on battery power but like you said for a desktop it doesn’t make sense. It seems like a simple thing to fix too.

I definitely wouldn’t want to force eject. I’m actually not sure why there’s so many processes accessing my drive since the data isn’t changing that much on it. I get around 5 power cycles an hour due to them.
 
Yup, I've seen Jettison and to be honest I don't see the point in it.

One use case would be a backup drive. Mine gets disconnected often. This could solve that. I will give it a try.
 
Samsung-990-Pro_OWC-1M2_081220251545.pngSamsung-990-Pro_Unsafe-Shutdowns_OWC-1M2_081220251545.png
From what I could uncover, the only real possibility of data corruption is, by the SSD controller not receiving a shutdown command, the buffer data may not have been dealt with, including but not limited to purged.

I tried to find official/expert sources but only came across forum posts.

If it makes you feel any better, the problem(?) is not specific to macOS. It actually doesn’t appear limited to external drives. One example:


P.S. The WD_BLACK SN850X I have in another 1M2 has over 25k unsafe shutdowns. One of the SSDs I’m using as a Time Machine drive has nearly 8,500 unsafe shutdowns recorded. I haven’t seen any data corruption.
 
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From what I could uncover, the only real possibility of data corruption is, by the SSD controller not receiving a shutdown command, the buffer data may not have been dealt with, including but not limited to purged.

I tried to find official/expert sources but only came across forum posts.

If it makes you feel any better, the problem(?) is not specific to macOS. It actually doesn’t appear limited to external drives. One example:


P.S. The WD_BLACK SN850X I have in another 1M2 has over 25k unsafe shutdowns. One of the SSDs I’m using as a Time Machine drive has nearly 8,500 unsafe shutdowns recorded. I haven’t seen any data corruption.
wow I got rookie numbers compared to you. How long have you had the drive for?

Maybe the risk for data corruption is low (none?) because this will only happen if the Mac mini is sleeping. I don't know if the Mac mini reduces the power right away to the ports or if that's only done after sleeping for a prolonged amount of time. In either case, if the Mac is sleeping, the external drive isn't being written to so there won't be any buffer data, or the ssd's read/write speeds are fast enough that it has enough time to write the buffer data between the time it takes the Mac mini to sleep and unsafely shutdown the drive.
 
Quite a thread we got going.

On my external (WD SN850X) are my Lightroom image files, my Photos library, a couple of Music libraries a symlinked folder for MobileSync/Backup (5 devices), some relatively dormant folders and a partition for a clone of the Studio. About 3 tb, out of 4, in use, pretty much constant data access, more than the internal.

I’ve been using Jettison since Mountain Lion primarily on MacBooks. Never had an issue. It dosen't eject a drive if it’s in use. At times I see a delay in sleep so I assume it has sufficient intelligence to subsequently invoke sleep. When I wake the Studio the drives are back before my ASD, which as any ASD owner can attest, is very fast. On the website is an FAQ dealing with oddball situations and how to deal with them.
 
Quite a thread we got going.

On my external (WD SN850X) are my Lightroom image files, my Photos library, a couple of Music libraries a symlinked folder for MobileSync/Backup (5 devices), some relatively dormant folders and a partition for a clone of the Studio. About 3 tb, out of 4, in use, pretty much constant data access, more than the internal.

I’ve been using Jettison since Mountain Lion primarily on MacBooks. Never had an issue. It dosen't eject a drive if it’s in use. At times I see a delay in sleep so I assume it has sufficient intelligence to subsequently invoke sleep. When I wake the Studio the drives are back before my ASD, which as any ASD owner can attest, is very fast. On the website is an FAQ dealing with oddball situations and how to deal with them.
I just tested with Jettison and my Photos library is preventing the drive from ejecting. The process"photolibraryd" is always running and sometimes "photoanalysisd" and "mediaanalysisd" also are. These are background processes that run even when the Photos app isn't open.
 
I just tested with Jettison and my Photos library is preventing the drive from ejecting. The process"photolibraryd" is always running and sometimes "photoanalysisd" and "mediaanalysisd" also are. These are background processes that run even when the Photos app isn't open.
I haven’t seen that in a long time. I might have killed them as I don’t need Apple sorting my images or it eventually completed doing whatever it’s doing. To kill: https://www.getdroidtips.com/disabling-mediaanalysisd-photoanalysisd-photolibraryd/
 
Interesting thread. There's serious problems with the whole TB thing everywhere. Seen it on windows too as much as macOS. I tend to just avoid the hell out of it now. NVMe disk on cheap ass PC motherboard? Rock solid. Shove it in a TB enclosure? Urgh.

I will note no problems at all on USB 3.2 Gen 2 with Samsung T7 shield disks...
 
Beware of OWC enclosures; they are known for not having correct firmware in their enclosures.

Example: I bought 4 enclosure a few years back: The problem is that you could not change a drive from one enclosure to another; even though they were the same enclosures. Lost 30 years worth of work before OWC tech support told me that there was a problem with the firmware on the enclosures. Took 3 years to recover all the lost data.
 
Beware of OWC enclosures; they are known for not having correct firmware in their enclosures.

Example: I bought 4 enclosure a few years back: The problem is that you could not change a drive from one enclosure to another; even though they were the same enclosures. Lost 30 years worth of work before OWC tech support told me that there was a problem with the firmware on the enclosures. Took 3 years to recover all the lost data.
Were those drives that came with the enclosure?
 
I experienced this issue a few years ago with Realtek RTL9210B-CG based NVMe enclosures. The unsafe shutdown count would increment by 1 for every safe eject, or any time the computer went to sleep mode. I eventually found a firmware update for that Realtek chip which resolved the issue. Since then, I’ve moved to Acasis and OWC Thunderbolt 3 enclosures that don’t exhibit this problem.

If multiple users are experiencing this with the 1M2 enclosures, I am sure OWC can work with ASMedia to implement a fix.

 
I think I found an adequate work around. I got Jettison to work so that the drive is ejected when the Mac sleeps. Since the photos app was the reason that ejecting wasn’t working, I created a second user account with a photos library that downloads all my pics to the external ssd, and changed my main login user to use optimized photos and have the library in the internal ssd. So the photos app is no longer accessing the external ssd unless I login to the secondary user, which I’ll be doing occasionally to sync my pics to the external ssd which I can then use for my backup. There haven’t been unsafe shutdowns since I’ve set this up. Edit: I jinxed it, I got another.

This solution isn’t perfect though. If in the future I have other app data on the external ssd it could prevent the ssd from ejecting too. The photos app was especially problematic since it runs background jobs when it’s closed. I’m hoping that for most apps, simply closing it will be enough to allow the sdd to eject. Fingers crossed.
 
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I have the same setup as you, Samsung 990 pro with an OWC express 1m2 enclosure, but with a 2TB SSD. My photo library lives on the external, as does my music libray. I regularly turn the machine off at night and when out of the house, but use sleep during most of the day.

When sleeping, often the SSD external shows being accessed, when the machine should definitely be asleep, with the 1m2's white light blinking at me annoyingly. And similarly "photolibraryd", "photoanalysisd" and "mediaanalysisd" show up too.

I've forced quit sometimes rather than shutting down everything. No issues from that I can find so far, but I wasn't doing anything with the data on the external when I did that.

I though maybe spotlight was indexing the photo library, tried to stop it from doing so. Either my efforts didn't work, or that's not the problem, because it didn't solve the problem. It keeps have this problem.

But not always. Sometimes it sleeps on, no stirring, though the night, like a content child.

Thanks for posting on this. Keep us posted if your approach is working. Or not.
 
I have the same setup as you, Samsung 990 pro with an OWC express 1m2 enclosure, but with a 2TB SSD. My photo library lives on the external, as does my music libray. I regularly turn the machine off at night and when out of the house, but use sleep during most of the day.

When sleeping, often the SSD external shows being accessed, when the machine should definitely be asleep, with the 1m2's white light blinking at me annoyingly. And similarly "photolibraryd", "photoanalysisd" and "mediaanalysisd" show up too.

I've forced quit sometimes rather than shutting down everything. No issues from that I can find so far, but I wasn't doing anything with the data on the external when I did that.

I though maybe spotlight was indexing the photo library, tried to stop it from doing so. Either my efforts didn't work, or that's not the problem, because it didn't solve the problem. It keeps have this problem.

But not always. Sometimes it sleeps on, no stirring, though the night, like a content child.

Thanks for posting on this. Keep us posted if your approach is working. Or not.

I have the 2 TB too so your setup is the same as mine. If you want to minimize those photos processes, you can do what I did, I followed this guide: https://forums.macrumors.com/thread...rnal-ssd.2351777/?post=31738760#post-31738760

Spotlight could be contributing to this but some of the folders in my external drive are backed up in Time Machine and I believe spotlight is needed to make that work so I left it on. I don't think that disabling it would fix it though. The Mac mini seems to wake up for all kinds of reasons and when it does it also turns on the external drive, even when it's ejected but still plugged in. That's why I'm still getting unsafe shutdowns with Jettison, although I think it's less frequent. I need to test it for a couple of days.

I've set up Jettison so that it doesn't remount the drive when the Mac wakes up so the unsafe shutdowns don't bother me as much since I know the drive wasn't being accessed and there's no risk of data corruption. What is concerning me is that the Mac mini wakes up the drive a handful of times an hour when it sleeps. I don't think that having such a high number of power cycles is good for the drive.

Maybe the best thing to do is to prevent the Mac mini from sleeping and turning it off before going to bed.
 
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