Mac OSX Monterey External Hard Disks Going to Sleep

Not always. My disk will spin up/down while ejected (not mounted) EVER! As long as it's connected, it keeps spinning up and down.

Which leads me to believe it's a fairly low level problem in the driver stack.

Continuing to monitor my Disk Not Ejected properly issue (which may or may not be related to disks spinning up and down frequently):

I have two OWC miniStackSTX boxes (Thunderbolt 4) with 14T hard drives used only for Time Machine. One is connected to a Mac Studio with an Apple 3 m Thunderbolt 4 cable. The other is daisy chained to the first drive. Nothing else is on this Thunderbolt chain.

After three months of testing ports, switching the positions in the Thunderbolt chain and monitoring and record keeping, I can say for certain that that the drive in the OWC miniStackSTX box daisy chained (#2 in the Thunderbolt chain) spontaneously ejects much more often than the directly connected drive.

Same problem here, seems to happen less with my Lacie RAID thunderbolt drive, but happens all the time with my USB 3.1 drive plugged directly into the rear ports on a M1 Max Studio. Every time I open up finder it beach balls for 10 seconds before showing the folders. Tried other cables, unchecked all the "put drives to sleep" check boxes, downloaded amphetamine...

Seems to work better after a restart for some unknown reason but starts spinning up and down constantly after a few minutes

"Have you tried changing the disksleep settings in Terminal?"

I experimented with several settings shorter than the default 10 minutes.

Note that the issue I'm dealing with is external hard drives spontaneously unmounting*, not a spin-up, spin-down problem.

*sometimes the drives remount on their own, sometimes I have to restart or unmount all and unplug and replug the Thunderbolt cable.

"Right. It seems that this thread is simultaneously discussing two different issues: one is mount/unmount problem and the other is a disk sleep problem, which was my problem."

Is there a way to ask a moderator to separate the threads?

HASSLE is right.

I've got an OWC Raid also, with MacStudio running MacOS 12.4.

Editing in Premiere and leaving the app every now & then for other tasks... only to hear RAID spinning up again when returning to Premiere is really getting old.

[And it's now 8 months since your post– and still no solutions from Apple.]

I could be wrong (and do tell me if I am) but I think using the pmset command to set the disksleep time is only applicable to the internal disk/s and would not apply to disks connected to a Thunderbolt port. Do say if this is not the case so not to leave any incorrect info here.

My external hard drives are only used for Time Machine, so spinning down is not an issue for me.

I did notice after the macOS 12.5.1 update that one of my drives spun up before my Mac Studio had completely rebooted. Clearly, the drive did that on its own, unrelated to the Mac Studio.

Update on my separate hard drive issue of drives spontaneously unmounting and producing one or more Notifications that the drive was not ejected properly—

Background: two OWC miniStack STX boxes Thunderbolt 4 daisy chained from a Mac Studio. Each box has a 14T hard drive. One box also has a 4T SSD. Everything's Thunderbolt 4. I've tested every configuration I could think of and several different Thunderbolt 4 cables.

I have logged as many Notifications as I could, and noticed that the second OWC miniStack STX on the Thunderbolt 4 daisy chain spontaneously ejected much more often that the one plugged directly into the Mac Studio. So I plugged both drives into my Mac Studio directly, so there's no daisy chaining. Ten days have passed with no spontaneous unmounting.

I ordered a second 3m Apple Thunderbolt 4 cable so I can have both drives located where I want them.

This is an expensive solution and shouldn't be necessary. I think it clearly implicates something about Thunderbolt 4. But I can live with this solution.

That's an interesting theory, except for many of us have used these drives with Intel Macs with VERY different behaviors.

We aren't talking about normal drive spin-down here. I expect and want my drive to spin-down!

What I don't want is for a drive that isn't in use to spin back up, then down, then back up, every few minutes. That is not normal!

With my drives connected to an Intel Mac, the behavior is as expected.

HI Nellisoft, OK, that's useful to know. I did the pmset command before changing the drives out and haven't changed it from 0 since, so that could fit in with your theroy. I'm waiting for delivery of 4 Seagate Iron Wolf drives, I'll swap them out with the drives in the two older LaCie enclosures and post what I find. For now the newer 2Big Dock Thunderbolt 3 is still not spinning down, whereas the the two older units are. This inconsistency in external drive behavior, one remaining up and two spinning down after 60 seconds, still makes me think it might be the drive type. I have tried them on different thunderbolt ports to try and remove the ports as an issue.

macOS 12.5.1 still doesn't fix the problem for me an my G-Tech drive.

Even with "Put hard disks to sleep when possible" disabled, and pmset showing a value of 0 for "disksleep", my drive is still spinning down, and up, and down.

Same issue for me, 2x WD Red (WD40EFAX) in Akasa USB box, formatted with APFS & RAID. MBP 13" M1, Monterey 12.5.1 and still not resolved. It's painful since I have a Lightroom library in that RAID array and disks are going down/up many times when working with my photos. I am certain this issue started a month or two ago, maybe after some update. Apple, please, get this resolved.

"Ten days have passed with no spontaneous unmounting.

I ordered a second 3m Apple Thunderbolt 4 cable so I can have both drives located where I want them."

Ten more days have passed with no spontaneous unmounting after installing the second 3m Apple Thunderbolt 4 cable.

Oddly, the disk spontaneously unmounted twice the morning after I moved it the first time and connected it directly to my Mac Studio. Exactly the same thing happened when I moved the disk a second time and installed the 3m Apple Thunderbolt 4 cable.

But after spontaneously unmounting twice in quick succession after each move, the system's been completely stable.

(Note that I'm not monitoring unusual spin up and spin down as my disks are used only for Time Machine.)

Just to add more data points, when I wake my MacStudio up in the morning, it tells me my time machine drive was dismounted incorrectly, plus sleep disconnects my printer (ethernet through a caldigit hub) when it goes to sleep so I have to restart my machine whenever I want to print anything. I'm thinking I should just shut my machine down at night rather than letting it sleep, but that's a work around, not a fix.