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sebalvarez

macrumors regular
Original poster
Apr 15, 2022
153
60
My very trusty late 2015 27” iMac, with a 3 TB Fusion drive, didn’t boot all of a sudden on Thursday morning. No warnings, it was fine as usual up until the night before on Wednesday, then the next morning, it boots to the “prohibited” circle. I’m not really upset for the drive failing, after all, it’s been in almost constant use for 5 years. It does upset me that I got no warning. I got about a dozen drives fail on me on PCs, but at least I was able to recover some files. In this case, it didn’t give me any warning, and while I didn’t lose everything because some of the files were in iCloud, I did lose some files that they are not the end of the world, but I’d rather have (please save any comments about how important it is to have a Time Machine backup, etc, etc, because I already know that.)

None of the usual stuff worked. “diskutil resetFusion” fails with errors because the SSD is fine, but the 3 TB HDD is broken. In fact, in Disk Utility, it shows as a 4.14 GB drive. So I’m guessing the pickup inside the drive is broken (I’m not sure if it’s called that, but you know what I mean, the thing that goes insanely fast back and forth reading the data.)

I’m going to get a Mac Studio soon, so I would prefer not to spend money and time on this machine, I just need it for a couple of months. But here’s the problem: my macOS Monterey install to an external Samsung T5 1 TB drive keeps giving me kernel panics either a few minutes or even half an hour after I boot it up, which I’ll paste at the end of this post for your reading pleasure.

There could be two reasons for this:

1) Most likely, because the OS tries to get information from the HDD drive and it’s broken. However, I have never seen that behavior in any computer, Mac or PC. In all the drives that failed me in the past, the broken drive wouldn’t work, but that didn’t cause any kernel panics on Macs or PCs.

2) A more unlikely reason might be that I wasn’t able to install macOS to the external SSD on the iMac itself, because I tried many times and it kept rebooting after a while and that would happen over and over. So I had to do the installation on my Macbook Pro, then connect the external SSD to the iMac. Other than the kernel panics, everything works fine. I don’t know if installing macOS on one machine, and then moving the external drive to use that installation in another Mac can cause problems, because I’ve never done it before.

Ideally, even if I’m getting a Mac Studio, I would like to keep this iMac as secondary machine, maybe for my wife. So keeping it working with the external SSD sounds great, but this random kernel panic thing is a problem obviously, and makes it useless if I don’t know when it’s going to crash. I would like to add that maybe it has to do with some sleep settings (even though I disabled the “Put hard disks to sleep when possible” setting) because as I’m writing this, the last kernel panic was like an hour ago, and usually they happen much sooner.

So if anyone has any ideas on how to prevent the kernel panics without having to disassemble the machine, take out the HDD and so on, I would really appreciate it.

One thing that just occurred to me is this: what if there’s a way to prevent the kext or driver for the Intel 10 SATA chip (the chip the drive is connected to, according to the system profiler) from loading? I mean, wouldn’t that basically prevent the kernel panics?

This is the kernel panic (I don’t know if they are different in any way, but I know it’s always the AppleAHCIDiskQueueManager and they all look the same. This is just the second to last one. I stopped copying and pasting them to TextEdit because I figured they are all the same or almost):

panic(cpu 0 caller 0xffffff8003c2c081): AppleAHCIDiskQueueManager::setPowerState(0xffffff9509bed240 : 0xffffff8005b7fcf0, 3 -> 0) timed out after 100360 ms @IOServicePM.cpp:5524
Panicked task 0xffffff95092f4670: 223 threads: pid 0: kernel_task
Backtrace (CPU 0), panicked thread: 0xffffff903daeaaa8, Frame : Return Address
0xffffffe12e3aba30 : 0xffffff8003483e2d
0xffffffe12e3aba80 : 0xffffff80035e3cb6
0xffffffe12e3abac0 : 0xffffff80035d350d
0xffffffe12e3abb10 : 0xffffff8003423a60
0xffffffe12e3abb30 : 0xffffff80034841fd
0xffffffe12e3abc50 : 0xffffff80034839b6
0xffffffe12e3abcb0 : 0xffffff8003d164bf
0xffffffe12e3abda0 : 0xffffff8003c2c081
0xffffffe12e3abe00 : 0xffffff8003c2b849
0xffffffe12e3abe10 : 0xffffff8003c45bae
0xffffffe12e3abe50 : 0xffffff8003c2a668
0xffffffe12e3abe70 : 0xffffff80034d71f5
0xffffffe12e3abee0 : 0xffffff80034d82c2
0xffffffe12e3abfa0 : 0xffffff800342318e

Process name corresponding to current thread (0xffffff903daeaaa8): kernel_task

Mac OS version:
21E258

Kernel version:
Darwin Kernel Version 21.4.0: Fri Mar 18 00:45:05 PDT 2022; root:xnu-8020.101.4~15/RELEASE_X86_64
Kernel UUID: B6F8637B-0844-355F-8C82-60FA06149384
KernelCache slide: 0x0000000003200000
KernelCache base: 0xffffff8003400000
Kernel slide: 0x0000000003210000
Kernel text base: 0xffffff8003410000
__HIB text base: 0xffffff8003300000
System model name: iMac17,1 (Mac-B809C3757DA9BB8D)
System shutdown begun: NO
Panic diags file available: NO (0xe00002bc)
Hibernation exit count: 0

System uptime in nanoseconds: 1895977375917
Last Sleep: absolute base_tsc base_nano
Uptime : 0x000001b9710ee076
Sleep : 0x0000000000000000 0x0000000000000000 0x0000000000000000
Wake : 0x0000000000000000 0x000000279d45f337 0x0000000000000000
Compressor Info: 0% of compressed pages limit (OK) and 0% of segments limit (OK) with 0 swapfiles and OK swap space
Zone info:
Foreign : 0xffffff800b0a3000 - 0xffffff800b0b1000
Native : 0xffffff803c728000 - 0xffffffa03c728000
Readonly: 0xffffff85093f4000 - 0xffffff86a2d8d000
Metadata: 0xfffffff0d24e1000 - 0xfffffff0f27f8000
Bitmaps : 0xfffffff0f27f8000 - 0xfffffff0fe7f8000

last started kext at 85011336924: @filesystems.smbfs 4.0 (addr 0xffffff7f9c938000, size 483328)
last stopped kext at 549273761932: >IOPlatformPluginLegacy 1.0.0 (addr 0xffffff7f9c5b1000, size 36864)
loaded kexts:
@filesystems.smbfs 4.0
>!ATopCaseHIDEventDriver 5440.11
>AudioAUUC 1.70
>!APlatformEnabler 2.7.0d0
>AGPM 127
>X86PlatformShim 1.0.0
@filesystems.autofs 3.0
>!AMikeyHIDDriver 131
>!AUpstreamUserClient 3.6.9
@kext.AMDFramebuffer 4.0.8
@kext.AMDRadeonX4000 4.0.8
@kext.AMDRadeonServiceManager 4.0.8
>!AHDA 340.2
>!AMikeyDriver 340.2
>eficheck 1
>!A!ISKLGraphics 18.0.5
>!A!IPCHPMC 2.0.1
>!AGraphicsDevicePolicy 6.5.7
@AGDCPluginDisplayMetrics 6.5.7
@kext.AMD9000!C 4.0.8
>pmtelemetry 1
|IOUserEthernet 1.0.1
>usb.!UUserHCI 1
>!AHV 1
>!ADiskImages2 126.100.13
>!A!ISKLGraphicsFramebuffer 18.0.5
>!AThunderboltIP 4.0.3
>!AMCCSControl 1.15
>!ASMCLMU 212
>!A!ISlowAdaptiveClocking 4.0.0
|SCSITaskUserClient 456.100.7
>!AFileSystemDriver 3.0.1
@filesystems.tmpfs 1
@filesystems.lifs 1
@filesystems.hfs.kext 583.100.10
@BootCache 40
@!AFSCompression.!AFSCompressionTypeZlib 1.0.0
@!AFSCompression.!AFSCompressionTypeDataless 1.0.0d1
>AirPort.BrcmNIC 1400.1.1
>!ASDXC 3.2.1
|!ABCM5701Ethernet 11.0.0
@filesystems.apfs 1934.101.3
>!AAHCIPort 351.100.4
@private.KextAudit 1.0
>!AACPIButtons 6.1
>!ARTC 2.0.1
>!ASMBIOS 2.1
>!AACPIEC 6.1
>!AAPIC 1.7
@!ASystemPolicy 2.0.0
@nke.applicationfirewall 402
|IOKitRegistryCompatibility 1
|EndpointSecurity 1
@Dont_Steal_Mac_OS_X 7.0.0
@kec.!AEncryptedArchive 1
>driverkit.serial 6.0.0
|IOSerial!F 11
>!AHIDKeyboard 228.1
>!AMultitouchDriver 5440.11
>!AInputDeviceSupport 5440.6
>!AHS!BDriver 5440.11
>IO!BHIDDriver 9.0.0
@kext.triggers 1.0
@kext.AMDRadeonX4070HWLibs 1.0
@kext.AMDRadeonX4000HWServices 4.0.8
>DspFuncLib 340.2
@kext.OSvKernDSPLib 529
>!AAudioClockLibs 140.1
>!ASMBusPCI 1.0.14d1
>!AHDA!C 340.2
|IOHDA!F 340.2
|IOAudio!F 340.2
@vecLib.kext 1.2.0
>!AGraphicsControl 6.5.7
@kext.AMDSupport 4.0.8
|IO!BSerialManager 9.0.0
|IO!BPacketLogger 9.0.0
|IO!BHost!CUSBTransport 9.0.0
|IO!BHost!CUARTTransport 9.0.0
|IO!BHost!CTransport 9.0.0
>IO!BHost!CPCIeTransport 9.0.0
|CSR!BHost!CUSBTransport 9.0.0
|Broadcom!BHost!CUSBTransport 9.0.0
|Broadcom!B20703USBTransport 9.0.0
>!AIPAppender 1.0
|IOAccelerator!F2 462.8
|IONDRVSupport 594
>!AThunderboltEDMSink 5.0.3
>!ASMBus!C 1.0.18d1
|IOAVB!F 1040.6
@plugin.IOgPTPPlugin 1040.3
|IOEthernetAVB!C 1.1.0
>X86PlatformPlugin 1.0.0
>IOPlatformPlugin!F 6.0.0d8
@plugin.IOAVBDiscoveryPlugin 1040.6
@!AGPUWrangler 6.5.7
@!AGraphicsDeviceControl 6.5.7
|IOGraphics!F 594
|IOSlowAdaptiveClocking!F 1.0.0
>usb.IOUSBHostHIDDevice 1.2
>usb.cdc 5.0.0
>usb.networking 5.0.0
>usb.!UHostCompositeDevice 1.2
>!AThunderboltDPOutAdapter 8.5.1
>!AThunderboltDPInAdapter 8.5.1
>!AThunderboltDPAdapter!F 8.5.1
>!AThunderboltPCIDownAdapter 4.1.1
>!ABSDKextStarter 3
|IOSurface 302.14
@filesystems.hfs.encodings.kext 1
>!AThunderboltNHI 7.2.81
|IOThunderbolt!F 9.3.3
|IO80211!FLegacy 1200.12.2b1
|IOSkywalk!F 1.0
>corecapture 1.0.4
>mDNSOffloadUserClient 1.0.1b8
>!A!ILpssI2C 3.0.60
>!AXsanScheme 3
|IOAHCIBlock!S 333.100.3
>usb.!UHostPacketFilter 1.0
|IOUSB!F 900.4.2
>!A!ILpssGspi 3.0.60
|IOAHCI!F 297
>usb.!UXHCIPCI 1.2
>usb.!UXHCI 1.2
>!AEFINVRAM 2.1
>!AEFIRuntime 2.1
|IOSMBus!F 1.1
|IOHID!F 2.0.0
|IOTimeSync!F 1040.3
|IONetworking!F 3.4
>DiskImages 493.0.0
|IO!B!F 9.0.0
|IOReport!F 47
$quarantine 4
$sandbox 300.0
@Kext.!AMatch 1.0.0d1
|CoreAnalytics!F 1
>!ASSE 1.0
>!AKeyStore 2
>!UTDM 533.100.11
|IOUSBMass!SDriver 210.101.2
|IOSCSIBlockCommandsDevice 456.100.7
|IO!S!F 2.1
|IOSCSIArchitectureModel!F 456.100.7
>!AMobileFileIntegrity 1.0.5
$!AImage4 4.2.0
@kext.CoreTrust 1
>!AFDEKeyStore 28.30
>!AEffaceable!S 1.0
>!ACredentialManager 1.0
>KernelRelayHost 1
|IOUSBHost!F 1.2
>!UHostMergeProperties 1.2
>usb.!UCommon 1.0
>!ABusPower!C 1.0
>!ASEPManager 1.0.1
>IOSlaveProcessor 1
>!AACPIPlatform 6.1
>!ASMC 3.1.9
|IOPCI!F 2.9
|IOACPI!F 1.4
>watchdog 1
@kec.pthread 1
@kec.Libm 1
@kec.corecrypto 12.0
 
It does upset me that I got no warning. I got about a dozen drives fail on me on PCs, but at least I was able to recover some files. In this case, it didn’t give me any warning
Unfortunately it does happen occasionally. I still remember maybe a decade ago, my computer was running with no issues, and then out of the blue it popped up the "next time, eject the drive before you unplug it" message. The drive had spontaneously failed with no warning whatsoever. In that case it was a separate data drive rather than part of a Fusion setup.

I'm afraid I can't help with your actual question. There might be some sort of obscure nvram command that'll let you disable the drive (akin to disabling it in the BIOS on an old PC) but I can't help you there. Hopefully one of the experts sees this thread :)
 
I discovered something new since I wrote this post. This kernel panic seems to be related to idling. When I wrote this post, I had had the machine on without a panic for about an hour, but during that time, I was using it. Then I went to the kitchen to get me something to eat, and when I came back, it had had the kernel panic. So I didn't touch it at all, while I was eating and watching TV, for like half an hour, but I had it on the desk next to me, so I saw what happened.

And that was that when it's not being operated in any way, no keyboard or mouse input, the kernel panic happens every five minutes or so.

So I'm almost positive there's something going on when the machine is idle that causes it to try to interact in some way with the broken drive, and I can't imagine why. I mean, the OS should only interact with the drives that are mounted, the rest, it shouldn't care about.
 
A thought: Maybe setting "disksleep 0" with the pmset command-line tool will help. I'm about to be late for work so can't elaborate right now!
 
If you run the machine entirely from an external USB SSD box, and dismount the internal drive, will the issue re-occur?
If you meant unmount the drive, the drive doesn't mount at all. If you mean physically taking it out, no, that's what I'm trying to avoid.
 
Does this occur when the iMac is idle and trying to go to sleep? If so, have you tried setting it so the iMac never sleeps?
Yes, I set it to never sleep, I only set it to turn off the screen at like 20 minutes or so, but it crashes way before that.
 
I have the same exact problem. Anyone found solution ? Thanks you :/
Probably there is no solution. It's a flaw in a great OS, maybe a situation that Apple's programmers never came across, a failing hard drive that takes down the whole OS. I've had drives fail in Windows before, and they never took down the system, they were not readable.
But if your drive is dead, forget about it. If it gets to the point where Disk Utility sees it as a 4 GB drive and it doesn't mount, you can't save it, unless you find another new drive of the same batch.

Eventually I cut my losses and spent $300 in a new SSD kit from Macsales.com, and spend a few hours very carefully replacing it. But you get a nice speed bump, my iMac is much faster with it.
 
I have exactly the same problem and was going to remove the faulty SSD but tried running caffeinate in terminal (keeps the OS from sleeping) and seems to be doing the trick.
 
Thanks for posting. Just had the same issue with my 2017 iMac 5k with 3tb fusion. Shows as 4tb in disk utility and kernel panics after a few minutes. Going to try the Fusion Drive replacement via owc kit.
 
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I think any Fusion Drives still in active use will all be dying over the next couple years. If it's not the HDD crapping out, it'll be the tiny (and very actively used) SSDs hitting their end of life.

Thanks for posting. Just had the same issue with my 2017 iMac 5k with 3tb fusion. Shows as 4tb in disk utility and kernel panics after a few minutes. Going to try the Fusion Drive replacement via owc kit.
I did the same a few years ago with my 2014 iMac 5K -- though I think I got my kit from iFixit. Probably the same basic kit. Anyway, it was a minor PITA but totally doable. Most of the time was spent getting all the old adhesive off the display, to have a clean surface to affix the new adhesive strips. I ended up pulling out the SATA hard drive and replacing it with a SATA SSD, and got a couple more years usable life out of the iMac.
 
I have the same issue. Internal Fusion Drive was failing on both SSD & HDD parts.
I created an external bootable SDD with macOS & set that to be the default boot device. Copied all my data to that.
I then just “ignored” the internal Fusion Drive. All good for a while.

However, recently I’m getting kernel panics & reboots.
When rebooting, you get the "ignore, continue, eject" options.
The internal Fusion Drive has unfused itself & the HDD part is broken, & can’t be erased or accessed.

I’ve done two things which seemed to stop the kernel panics, but not sure which one had the desired result.

1. From a terminal prompt, issue this command (can’t seem be done from disk utility).
Note that my disk had already unfused itself
> diskutil list internal
This lists the drives inside. The one I’m after is /dev/disk1 (internal, physical, 4.1GB size)
> diskutil unmountDisk /dev/disk1

This might need to be done every re-boot, so schedule a script to do that if you reboot often.

2. The second thing I did was to go to:
system settings/energy saver And turn off “put hard disks to sleep when possible”. I think this is the more likely fix of the two
 
I have the same issue. Internal Fusion Drive was failing on both SSD & HDD parts.
I created an external bootable SDD with macOS & set that to be the default boot device. Copied all my data to that.
I then just “ignored” the internal Fusion Drive. All good for a while.

However, recently I’m getting kernel panics & reboots.
When rebooting, you get the "ignore, continue, eject" options.
The internal Fusion Drive has unfused itself & the HDD part is broken, & can’t be erased or accessed.

I’ve done two things which seemed to stop the kernel panics, but not sure which one had the desired result.

1. From a terminal prompt, issue this command (can’t seem be done from disk utility).
Note that my disk had already unfused itself
> diskutil list internal
This lists the drives inside. The one I’m after is /dev/disk1 (internal, physical, 4.1GB size)
> diskutil unmountDisk /dev/disk1

This might need to be done every re-boot, so schedule a script to do that if you reboot often.

2. The second thing I did was to go to:
system settings/energy saver And turn off “put hard disks to sleep when possible”. I think this is the more likely fix of the two
I'm not clear from your post if you were finally able to resolve the problem.

Regardless, I think it's really pathetic that a company like Apple releases a machine that has a drive that when it fails, you have no choice but to replace it. I mean, one advantage about Macs is that you can boot the OS from an external drive. But if the drive inside makes the machine freeze after a few minutes, it's still pointless.

In a Windows machine this wouldn't happen. You'd have to install a separate drive and reinstall Windows, but the broken drive wouldn't bring Windows down.

Good thing there's a company like OWC that sells good drives and kits to replace these drives, otherwise most users would be left with a machine they can no longer use.
 
Yes, it fixed it.

However since then I decided to replace the internal drive with an SSD anyway. I bought a complete kit from iFixIT which comes with all the required tools, an SSD drive & appropriate drive caddy. Not a difficult fix, but time consuming as I went slowly and carefully. The previous versions of iMac had the screen held on with magnets, but this version is attached with sticky stuff, which needs cleaning off carefully. There are step by step guides on the website if you want to gauge the level of difficulty.
 
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