My very trusty late 2015 27-inch iMac with a 3TB Fusion drive didn’t start up suddenly on Thursday morning. No warning, it was fine as usual until the day before Wednesday, then the next morning it starts in the “forbidden” circle. I’m not really upset about the drive failing, after all it’s been in use almost constantly for 5 years. It pisses me off that I didn’t get any warnings. I’ve had about a dozen crashed drives on me on PCs, but at least I was able to salvage some files. In this case, it gave me no warning, and while I didn’t lose everything because some files were in iCloud, I lost some files that they’re not the end of the world, but I prefer (please save any comments on the importance of having a Time Machine backup etc etc as I already know that.)

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

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

There can be two reasons for this:

1) Most likely, because the operating system is trying to get information from the hard drive and it is faulty. However, I have never seen this behavior on any computer, Mac or PC. In all disks that have failed me in the past, the broken disk didn’t work, but it didn’t cause any kernel panics on Macs or PCs.

2) A more unlikely reason could be that I couldn’t install macOS on the external SSD of the iMac itself, because I tried several times and it kept rebooting after a while and it was happening again again and again. So I had to do the install on my Macbook Pro and then connect the external SSD to the iMac. Other than kernel panics, everything works fine. I don’t know if installing macOS on one machine and then moving the external drive to use that install on another Mac can cause problems, as I’ve never done this before.

Ideally, even if I buy a Mac Studio, I’d like to keep this iMac as a secondary machine, perhaps for my wife. So getting it to work with the external SSD sounds great, but that random kernel panic is obviously a problem, and makes it useless if I don’t know when it’s going to crash. I would like to add that it may have to do with some sleep settings (even though I disabled the “Put hard drives to sleep when possible” setting) because as of this writing the latest kernel panics were about an hour ago, and usually they happen much earlier.

So if anyone has any ideas on how to prevent kernel panics without having to unmount the machine, remove the hard drive, etc., I would really appreciate it.

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

It’s Kernel Panic (I don’t know if they’re different in any way, but I know it’s still AppleAHCIDiskQueueManager and they all look the same. It’s just the second to last. J stopped copying and pasting them into TextEdit because I figured they’re all pretty much the same):

panic(cpu 0 calling 0xffffff8003c2c081): AppleAHCIDiskQueueManager::setPowerState(0xffffff9509bed240: 0xffffff8005b7fcf0, 3 -> 0) timed out after 100360ms @IOServicePM.cpp:5524
Panic 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 the 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
Slide KernelCache: 0x0000000003200000
Core cache base: 0xffffff8003400000
Core Slide: 0x0000000003210000
Core textbase: 0xffffff8003410000
Text base __HIB: 0xffffff8003300000
System Model Name: iMac17.1 (Mac-B809C3757DA9BB8D)
System shutdown started: NO
Panic diagnostic file available: NO (0xe00002bc)
Number of hibernation exits: 0

System availability in nanoseconds: 1895977375917
Last sleep: absolute base_tsc base_nano
Availability: 0x000001b9710ee076
Sleep: 0x0000000000000000 0x0000000000000000 0x0000000000000000
Wakeup: 0x0000000000000000 0x000000279d45f337 0x0000000000000000
Compressor Info: 0% compressed pages limit (OK) and 0% segments limit (OK) with 0 swap files and swap space OK
Area Information:
Abroad: 0xffffff800b0a3000 – 0xffffff800b0b1000
Native: 0xffffff803c728000 – 0xffffffa03c728000
Read only: 0xffffff85093f4000 – 0xffffff86a2d8d000
Metadata: 0xffffff0d24e1000 – 0xffffff0f27f8000
Bitmaps: 0xffffff0f27f8000 – 0xffffff0fe7f8000

kext last started at 85011336924: @filesystems.smbfs 4.0 (addr 0xfffff7f9c938000, size 483328)
kext last stopped at 549273761932: >IOPlatformPluginLegacy 1.0.0 (addr 0xfffff7f9c5b1000, size 36864)
kexts loaded:
@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
>!AAHCI Port 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
|IOSeries!F 11
>!AHIKeyboard 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
>!Appendix AIP 1.0
|IOAccelerator!F2 462.8
|IONDRVSupport 594
>>AThunderboltEDMSink 5.0.3
>!ASMBus!C 1.0.18d1
|IOAVB!E 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
>!A ThunderboltDP!F 8.5.1 Adapter
>>AThunderboltPCIDownAdapter 4.1.1
>!ABSDExtStarter 3
|IOSurface 302.14
@filesystems.hfs.encodings.kext 1
>>A ThunderboltNHI 7.2.81
|IOThunder!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
|IReport!F 47
$quarantine 4
$300.0 sandbox
@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
|Architectural model IOSCSI!F 456.100.7
>!AMobileFileIntegrity 1.0.5
$!AImage4 4.2.0
@kext.CoreTrust 1
>>AFDEKeyStore 28.30
>!AErasable!S 1.0
>!ACredentialManager 1.0
>KernelRelayHost 1
|IOUSBHost!F 1.2
>>UHostMergeProperties 1.2
>usb.!UCommon 1.0
>!ABusPower!C 1.0
>!ASEP Manager 1.0.1
> IOS 1 slave processor
>!AACPIPplatform 6.1
>!ASMC 3.1.9
|IOPCI!E 2.9
|IOACPI!F 1.4
> watchdog 1
@kec.pthread 1
@kec.Libm 1
@kec.corecrypto 12.0