SoftRaid constantly ejecting drive when Mac goes to sleep

This is a MacOS bug, related to "energy star" requirements for computers to power down.

A related bug, which is easily seen, is any disks that are connected to a mac, when it sleep, will power them up for 5 minutes or so, every 45 minutes. Even if you wipe the disks, so they have no partition map, this will happen. That proves this issue has nothing to do with any disk driver (Disk Utility, Apple RAID, SoftRAID, etc), but likely triggered by the regular wake from sleep to check for network activity.

We reported this long ago. Hopefully this will be fixed in MacOS sooner rather than later.

In the meantime, if you have your machine going to sleep, unmount/disconnect your drives at night. the only workaround for you otherwise, is to set all sleep settings to off.

I used to have tremendous problems with my OWC devices being ejected after we switched to Apple Silicon As a matter of fact, I couldn't use my expensive OWC RAID for nearly a year. There are plenty of my issues in the support forum.However this has been fine for the past two years but seems to be recurring. after Apple 15.5 update.

I'm not sure that this is a macOS bug because I also have:

• One Promise Pegasus RAID
• Two QNAP T4 RAIDs

All are connected, and none of them have issues after waking up. It's only OWC which was the same issue two years ago. My Promise Pegasus RAID would work without an issue but all 3 OWC Thunderbays became expensive paper weights. 

Multi posting is not helpful!

Your other enclosures do not tell you such issues. SoftRAID is very active on telling you what is going on with the drives. As mentioned, this may be a disk issue.

@softraid-support 

So, I had a deeper look into it and asked AI, which came back with a similar explanation to the one you gave However, it also seems to be the case that OWC enclosures are far more affected than those from other manufacturers which is in line with my experience. What is quite surprising, though, is that for the past two years I simply did not have the issue and I have not changed my setup besides OS updates. I can't really pinpoint it a hundred percent to 15.5, but since the update to 15.5, the issue has started occurring again. It seems like the hardware-raid based solutions deal much better with the issues than OWC's software approach?

I think SoftRAID should put a bit more pressure on Apple to solve the issue. It is ridiculous that I can't let my machine run overnight, where it does all the backup tasks and then goes to sleep, and instead have to shut it down every night.

The question is, if the Pegasus and QNAP don't report it, It seems to have had no adverse effect on the RAID, because they have been operating like this for quite some time. However, OWC seems to have an issue with it, because it needs to rebuild the RAID. Given the issues I had a few years ago, I'm a bit sceptical about who is blaming the fault on whom and who really is the culprit. The fact is that over the past four years, only OWC drives were noticeably affected by any of the issues, and in the case of a few years ago completely rendered useless for quite a few months. This is even more concerning because, to retain the full functionality of my OWC hardware, I have to pay the yearly subscription for the software so I guess I do expect more. Promise and Qnap both have management software yet I have never had to pay for an update or a subscription to retain full functionality of the hardware I purchased.

## OWC ThunderBay 4 Drive Ejection Issues on macOS

### Overview

Many users have reported problems with OWC ThunderBay 4 enclosures unexpectedly ejecting drives, especially overnight or during system sleep. This is a well-documented issue on Apple Silicon Macs and has persisted across multiple macOS versions, including recent updates. The problem is often accompanied by drives spinning up and down in regular cycles while the Mac is asleep.

### Key Findings

#### 1. **Widespread Issue, Not Limited to OWC**

- Numerous reports confirm that the problem is not unique to OWC ThunderBay 4; other Thunderbolt enclosures from various brands have also exhibited similar behavior on macOS, particularly with Apple Silicon systems[1][2].
- However, some users, like yourself, note that Promise Pegasus and QNAP RAID enclosures do not show the same ejection issues, even when connected to the same Mac and under the same sleep conditions. This suggests that the problem may be more prevalent or more easily triggered with certain hardware or firmware combinations[2][3].

#### 2. **Root Causes: Thunderbolt, macOS, and Sleep Behavior**

- The primary technical cause is related to how macOS manages Thunderbolt connections during sleep or hibernation. Thunderbolt is sensitive to signal interruptions, and any brief loss of connection—due to sleep cycles, cable quality, or system power management—can cause the drives to be ejected[1][2][4].
- macOS’s energy-saving features (influenced by "energy star" requirements) periodically wake the system to check for network activity or other tasks, which can trigger external drives to spin up and down every 45 minutes or so, regardless of their partition state[2][5].
- This behavior is not directly caused by disk drivers (such as SoftRAID, Apple RAID, or Disk Utility), as it occurs even when no drivers are installed and when disks are wiped clean[1][2].

#### 3. **Error Reporting Differences**

- OWC’s SoftRAID software is particularly proactive in reporting drive ejection and related events, which may give the impression that OWC hardware is less reliable, when in fact it may simply be more transparent about issues[1][4].
- Promise Pegasus and some other RAID systems may handle these events differently or may not report transient disconnects as aggressively, which could explain why you see more notifications from OWC devices[1][6].

#### 4. **No Simple Fix—Workarounds Only**

- Replacing enclosures, cables, disks, or power supplies rarely resolves the issue[1][3].
- The most reliable workaround is to prevent your Mac from sleeping or to manually unmount/disconnect external drives before sleep. Some users have had limited success with third-party utilities that keep the Mac awake, but these do not prevent the periodic spin-up/spin-down cycles[2][7].
- Adjusting macOS Energy Saver settings (disabling "Put hard disks to sleep when possible") may help, but is not always effective, especially on newer macOS versions[7][8].

### Table: Comparison of OWC ThunderBay 4 and Promise Pegasus RAID Behavior

| Feature/Issue | OWC ThunderBay 4 | Promise Pegasus RAID |
|------------------------------|----------------------------|----------------------------|
| Drive ejection during sleep | Frequently reported[1][2] | Rarely reported[2][9] |
| Aggressive error reporting | Yes (via SoftRAID)[1][4] | Less aggressive[6] |
| Affected by macOS sleep bug | Yes[1][2][4] | Less affected[2][9] |
| Workarounds | Disable sleep, unmount[1] | Not typically required[9] |

### Community and Vendor Responses

- OWC, Apple, and SoftRAID support have all acknowledged the issue but tend to attribute it to the other parties, resulting in a lack of definitive resolution[1][3][10].
- Users have reported the bug to Apple for several years, but it remains unresolved as of the latest macOS releases[2][11].

### Recommendations

- **If you must leave your Mac on overnight:** Set all sleep settings to off, or unmount/disconnect your ThunderBay 4 before sleep[1][2].
- **Monitor for updates:** Keep macOS and all related drivers/firmware up to date, as a future software update may address the underlying issue[7][8].
- **Consider alternative enclosures:** If the issue persists and is critical, using RAID enclosures known to be less affected (like Promise Pegasus) may be a temporary solution[2][9].

This issue is a complex intersection of hardware, macOS power management, and Thunderbolt protocol behavior. While OWC’s error reporting may make the problem more visible, the root cause lies largely with macOS’s handling of Thunderbolt devices during sleep and hibernation cycles[1][2][4].

Sources
[1] Disks Ejecting While In Use https://software.owc.com/knowledge-base/disks-ejecting-while-in-use/
[2] Thunderbay 4 ejecting multiple times in sleep - SoftRAID Forum https://forums.softraid.com/sonoma-issue/thunderbay-4-ejecting-multiple-times-in-sleep/
[3] OWC Thunderbay 4 DAS T3 connection to iMac drops regularly causing restart https://discussions.apple.com/thread/255666993
[4] Disk Eject Errors https://software.owc.com/knowledge-base/disk-eject-errors/
[5] Thunderbay 4 Disconnecting and Reconnecting throughout ... https://forums.softraid.com/macos-issues-2-2-big-sur-issues/thunderbay-4-disconnecting-and-reconnecting-throughout-sleep/
[6] Using promiseutil to Find a Failing RAID Member. - a modest blog https://blog.modestindustries.com/using-promiseutil-to-find-a-failing-raid-member/
[7] All External Drives Disconnecting after updating to Sonoma https://www.reddit.com/r/MacOS/comments/16um2co/all_external_drives_disconnecting_after_updating/
[8] Easily Resolve Mac External Hard Drive Sleep Problems https://www.stellarinfo.com/blog/resolve-mac-external-hard-drive-sleep-problem/
[9] Q&A: Broken promise https://eclecticlight.co/2015/01/21/qa-broken-promise/
[10] Does anyone have sleep issues with their OWC ThunderBay TB3 enclosures? https://forums.macrumors.com/threads/does-anyone-have-sleep-issues-with-their-owc-thunderbay-tb3-enclosures.2262633/
[11] External Drives STILL ejecting during sleep in Ventura https://discussions.apple.com/thread/254322044
[12] M1 MacBook Pro "Disk Not Ejected Properly… https://discussions.apple.com/thread/252115469?page=2
[13] Mac Mini 2013 wakes immediately after sleep when USB drive plugged in https://apple.stackexchange.com/questions/134617/mac-mini-2013-wakes-immediately-after-sleep-when-usb-drive-plugged-in
[14] PROMISE Pegasus32 R8 causes ridiculous system-wide freezes on ... https://github.com/lgarron/first-world/issues/100
[15] Support Manual for OWC ThunderBay 4 with Thunderbolt 3 https://eshop.macsales.com/manuals/owc-thunderbay-4-thunderbolt-3-support-manual
[16] "Disk Not Ejected Properly" Alert after computer goes to ... https://superuser.com/questions/950193/disk-not-ejected-properly-alert-after-computer-goes-to-sleep-usb3-only
[17] Panics, Pegasus, and Recovery - The Eclectic Light Company https://eclecticlight.co/2018/12/03/panics-pegasus-and-recovery/
[18] Can't disable sleep hard drives at all. - Apple Communities https://discussions.apple.com/thread/254863967
[19] OWC Thunder Bay 4 issue. https://bcgforums.com/threads/owc-thunder-bay-4-issue.9570/
[20] Is it better to sleep drives or leave them spinning in between ... - Reddit https://www.reddit.com/r/DataHoarder/comments/1cxn4y9/is_it_better_to_sleep_drives_or_leave_them/

Posted by: @juancano

↑

I saw a post form 3 years ago but no solutions. I'm on Mac OSX 15.5, althought this has been happening since I got the array. When my Mac goes to sleep it ejects and get error messages. When I come in the mornings, it's like 4-5 error messages. This is a daily occurrence and OWC hasn't figured out a solve.

 

Anyone else seeing this?

• Running OSX 15.5, New MacBook Pro M4 Max

• I have tried the Amphetamine to keep it awake but didn't work

• Mac set to not put HDs to sleep

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I just also tried amphetamine, but didn't make a difference to me either. Very strange. This has not happened until 15.5

, but since the latest update it happened Nearly every night and prevents me from keeping my machine on and doing my backups at night, which really defeats the purpose.

@steve223 
Test the Tahoe beta and see it is any better... (its pretty reliable, some third party utilities may have bugs)

@softraid-support I find it incredible that you asked me to install a beta Tahoe OS version on a production machine to use my OWC hardware. There is no way I'm testing a beta OS on my production machine where I need the SoftRAID. As a matter of fact, I won't install any new OS until version x.1 is out. I'm now also getting these issues when the machine is not asleep. I'm now shutting down the machine every night, but I'm suddenly getting disk out of sync errors when restarting, so the machine hasn't been asleep at all please fix the issues for Sequoia 15.5 asap.

@steve223 

This issue is a hardware or MacOS issue, 100%.

SoftRAID has zero to do with sleep type issues. Same with the disconnects, the SoftRAID driver simply tells MacOS where to put data, it has no mount/sleep capability, its all MacOS that does that.

You coudl install Tahoe on a separate system, or a separate computer. I was just making the suggestion. Or wait until the fall and see if Apple did fix this or not.

If this is a new bug, then it is clearly Sequoia related. Although I have not seen this specifically, and no related reports of this starting with  15.5.

Sorry, I cannot help more. SoftRAID is a filter driver, exactly as is Apple' RAID driver, except SoftRAID has more reporting and tracking. Its passive, meaning it cannot cause your issues, just report them.

Its like the issue when you put your system to sleep and every 45 minutes or so, they spin up. You can replicate that with any disks, whether SoftRAID, Apple format, windows format, or even unformatted drives. But since a Thunderbay has 4 drives, instead of one, its much noisier to the user, so they notice it more.

Posted by: @softraid-support

↑

Its like the issue when you put your system to sleep and every 45 minutes or so, they spin up. You can replicate that with any disks, whether SoftRAID, Apple format, windows format, or even unformatted drives. But since a Thunderbay has 4 drives, instead of one, its much noisier to the user, so they notice it more.

Has this issue been solved by macos Tahoe?

I have some Thunderbay units which I'm using less and less due to this issue of not respecting spindown (either once ejected, they spin up again or also during sleep they sometimes spin up again)

Please let us know, I don't have a spare machine to try it.

@shoptommasoalvisi-com 

No it has not been fixed yet. You can take any enclosure of multiple drives,  format them any way you want, including leaving them unformatted and put the system to sleep and you will hear them spin up every 45 minutes or so. 
Apple should be working on this, as it is such an obvious bug, and hopefully this is the macOS version that finally has the energy saving routines rewritten

I resolved this problem by setting my Mac (running Tahoe) to NOT apply my focus settings to all my devices ( Settings>Focus> Share across devices). Because this was turned on by default when I upgraded to Tahoe my iPhone focus settings were applied to my Mac, putting it to sleep during my sleeping hours and disconnecting my Thunderbay.

TL;DR: disabling screensleep did the trick for me.

I encountered the same problems after setting up a RAID. My setup is as follows: Mac Mini M4 (non-pro) with Sequoia 15.7.3. (I will not install Tahoe until the summer, i.e. not until version number 26.7.x, and I won't install at all and wait another year, if Tahoe remains as unstable as some users are currently reporting.) My storage pool consists of 6 * 4 TB SSDs (WD Red SA500, current generation), RAID5 optimized for server use. (I did not certify the SSDs, because I had done extensive testing with DriveDx after buying them a few weeks ago.) It's not an off-the-shelf Thunderbolt enclosure, but a DIY hack, because I wanted the whole build to fit into a 2U rackmount chassis (SilverStone RM23-502). So I'm using an IcyDock ExpressCage MB038SP-B enclosure for 8 SATA SSDs, which are connected via SATA cables to two M.2-Key-M-form-factor PCIe-to-6*SATA adapters, which use an ASM1166 chipset (PCIe gen3 x2 to 6xSATA controller), i.e. with a maximum of 1.969 GB/s per controller. Each of those adapters goes into its own Ugreen 40Gbps USB4/TB4 M.2 SSD enclosure, and the two Ugreens are attached to the Mac Mini's first two Thunderbolt ports. For maximum bandwidth, each enclosure addresses only three RAID5 SSDs, while the second enclosure also addresses the backup HDD, which is in an IcyBox IB-170SK-B enclosure. (Everything is powered with a 120W PicoPSU and a 150W power brick.)

My original power management configuration had a lot of sleep settings already disabled, but not displaysleep. With my original config, OWC lost track of at least one SSD, leading to an unmounting of the storage pool, and only a reboot could fix it, but the problem reappeared roughly after 15 minutes. I then set displaysleep to 0, i.e. I disabled it, and it's been running smoothly so far for almost 24 hours. The Mac Mini Server is running headless anyway, and only has an EDID dongle for the right 1080p resolution when logging into the UI (a) with Remote Desktop or (b) via a KVM switch, either directly on console or remotely through a PiKVM. So disabling display sleep doesn't really matter.

This is my current power management config – `pmset -g` output: 

 standby              0
 Sleep On Power Button 1
 autorestart          1
 SleepServices        0
 powernap             0
 networkoversleep     0
 disksleep            5
 sleep                0
 ttyskeepawake        1
 displaysleep         0
 tcpkeepalive         1
 lowpowermode         0
 womp                 1

(Please note that you can't disable "Sleep On Power Button" with `sudo pmset -a powerbutton 0` anymore on newer macOS versions. But for some reason, macOS still lists it.)

I am keeping the disksleep setting (after 5 minutes), because afaik this setting does not affect SSD performance, but I'll probably need it for my backup HDD: after cloning the storage pool to the HDD with Carbon Copy Cloner, I will always run a postflight script to wait 5+ minutes, i.e. wait for HDD spin-down ("disksleep"), then unmount and then eject/power-cycle down the HDD.

@anay 

Lot of custom work. One comment. "SoftRAID" cannot lose track of an SSD, that would have to be MacOS. However, I do not know of any MacOS bugs that trigger disks disappearing, I would bet the farm that was a hardware issue. I used to see a a fair amount of occurrences where an SSD would go missing, but as the technology matured, that rarely happens now.

Posted by: @juancano

↑

I saw a post form 3 years ago but no solutions. I'm on Mac OSX 15.5, althought this has been happening since I got the array. When my Mac goes to sleep it ejects and get error messages. When I come in the mornings, it's like 4-5 error messages. This is a daily occurrence and OWC hasn't figured out a solve.

 

Anyone else seeing this?

• Running OSX 15.5, New MacBook Pro M4 Max

• I have tried the Amphetamine to keep it awake but didn't work

• Mac set to not put HDs to sleep

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