Big Sur hang and crash at shutdown

So I can confirm that reformatting the time machine backup drive from HFS+ to APFS (and losing months worth of backups) fixed the crash on shutdown issue. As a parentheses, I wasted days trying to "convert" the HPFS+ to APFS only to realize that Time Machine can't reuse the old backup files anyway plus, First Aid was showing lots of errors past conversion. Don't repeat my mistake.

Best, back up to a third drive temporarily, then erase the main backup drive as APFS/case sensitive, then activate Time Machine on it and deactivate the third drive. ta-da.

The issue seems to be Kernel related with how the old driver's were installed vs how that are probably migrated under Big Sur. I resolved my issue by reinstalling the drivers for any external drives and the hang on shutdown issue went away.

Same issue here. I have an application called AutoMounter which does like it says and auto mounts (and auto remounts) my NAS for me: https://www.pixeleyes.co.nz/automounter/

’Pausing’ the auto mount function in there, manually unmounting the drives and waiting a few seconds resulted in the first clean shutdown in weeks!

This was never an issue before but seems big sur can’t unmount the drives like it used to be able to.

I temporarily solve the issue by STOPPING any ongoing job by TimeMachine before shutting down the computer. It's definetly related to the inability of BigSur to deal with TimeMachine software and whichever external unit (NAS in my case) to cease ongoing jobs properly before shutting down.

If I simply press the hotkeys combo to switch off the computer, it will instead panic and reboot with the error.

And 11.2.1 does not mention a fix for this either.

I wonder why in the friggin **** does Apple add a "REPORT" button on their OSs if they won't simply hear at it!?

Based on other feedback in this forum I did finally have time to format the R4i to APFS (case sensitive), which required a long backup and restore process as it serves as my primary data storage device. The Mac Pro only has the 256GB SSD.

The problem I have now is that my work based OneDrive is unable to use the R4i because it's incompatible with APFS (case sensitive.) I realize that technically isn't Apple's problem, but the R4i is promoted by Apple as a plug and play partner solution. It shouldn't require special formatting to prevent a major system issue with restarting and shutting the computer down.

I also have a similar problem on my new M1 Mac mini on Big Sur (11.1), a 40" 4k external display, and connected to 6 external drive enclosures, all Mac OS Extended (Journaled). Two of the enclosures are Promise Pegasus2 R4s (TB2), two are Akitio 4 bay units (TB2) and two are OWC 4 bay units (TB2 and TB3). I connected Mac Mini TB4 port to the OWC TB3 unit, then used an Apple TB3 to TB2 to connect other TB2 units. I'm using M1/Big Sur compatible Pegasus and Softraid drivers that have recently been made available and seem to work OK.

Booting up the M1 from a cold start works fine, but if try to shut down with all external drive units connected, after about 40 seconds, the Mini will restart with a panic notification (I copied the beginning part of the panic report below). If I remove just one of the drive enclosures from the TB chain, I can successfully complete a clean shut down. Only if I add the 6th unit does it panic. Btw, it took about 35 seconds to cleanly shut down with 5 units. And I can also cleanly shut down if no units are connected.

I'm now (obviously?) thinking that the problem has to do with the number of connected drive enclosures. When I connect these same 6 units to my Mac Pro (late 2013) on Catalina (10.15.7), I have no problems and it cleanly shuts down every time. The time needed to cleanly shut down all 6 units on Catalina is about 26 seconds, which is much shorter than when on Big Sur.

I've been able to bypass the problem by ejecting the 2 Promise units, disconnecting from TB chain, then shut down, but hopefully Apple can come up with a fix soon so I don't have to keep doing this.

---

panic(cpu 1 caller 0xfffffe001eef5678): "Halt/Restart Timed Out"

Debugger message: panic

Memory ID: 0x6

OS release type: User

OS version: 20C69

Kernel version: Darwin Kernel Version 20.2.0: Wed Dec 2 20:40:21 PST 2020; root:xnu-7195.60.75~1/RELEASE_ARM64_T8101

Fileset Kernelcache UUID: 3E6AA74DF723BCB886499A5AAB34FA34

Kernel UUID: 48F71DB3-6C91-3E62-9576-3A1DCEF2B536

iBoot version: iBoot-6723.61.3

secure boot?: YES

Paniclog version: 13

KernelCache slide: 0x0000000016b00000

KernelCache base: 0xfffffe001db04000

Kernel slide: 0x0000000017640000

Kernel text base: 0xfffffe001e644000

Kernel text exec base: 0xfffffe001e70c000

mach_absolute_time: 0xdab986b2

Epoch Time: sec usec

Boot : 0x5fe237e2 0x000d88d1

Sleep : 0x00000000 0x00000000

Wake : 0x00000000 0x00000000

Calendar: 0x5fe2386d 0x0007f0ab

CORE 0 recently retired instr at 0xfffffe001e876c5c

CORE 1 recently retired instr at 0xfffffe001e875798

CORE 2 recently retired instr at 0xfffffe001e876c5c

CORE 3 recently retired instr at 0xfffffe001e876c5c

CORE 4 recently retired instr at 0xfffffe001e876c60

CORE 5 recently retired instr at 0xfffffe001e876c60

CORE 6 recently retired instr at 0xfffffe001e876c60

CORE 7 recently retired instr at 0xfffffe001e876c60

Panicked task 0xfffffe166d004c70: 38253 pages, 512 threads: pid 0: kernel_task

Panicked thread: 0xfffffe16718f1fb8, backtrace: 0xfffffe308932b7a0, tid: 9734

lr: 0xfffffe001e759f8c fp: 0xfffffe308932b810

lr: 0xfffffe001e759d58 fp: 0xfffffe308932b880

lr: 0xfffffe001e87bf5c fp: 0xfffffe308932b8a0

lr: 0xfffffe001e86d914 fp: 0xfffffe308932b950

lr: 0xfffffe001e7137e8 fp: 0xfffffe308932b960

lr: 0xfffffe001e7599e8 fp: 0xfffffe308932bcf0

lr: 0xfffffe001e7599e8 fp: 0xfffffe308932bd60

lr: 0xfffffe001eef43f8 fp: 0xfffffe308932bd80

lr: 0xfffffe001eef5678 fp: 0xfffffe308932bd90

lr: 0xfffffe001e79b4d0 fp: 0xfffffe308932be10

lr: 0xfffffe001e79afac fp: 0xfffffe308932bf00

lr: 0xfffffe001e71cc14 fp: 0x0000000000000000

last started kext at 1109183920: com.apple.iokit.SCSITaskUserClient 436.40.6 (addr 0xfffffe001e3c8000, size 16384)

loaded kexts:

com.softraid.driver.SoftRAID 6.0.1b47

com.promise.driver.stex 6.2.16

com.apple.iokit.SCSITaskUserClient 436.40.6

com.apple.filesystems.autofs 3.0

... (additional report info removed)

I do not have the significant setup that some of you do, but I DO have the same problem. My newer iMac running Big Sur 11.1 often reboots or won't shut down properly. The next boot up shows an un-properly shut down machine, which I dutifully report. I have 2 external hard drives. 6GB and 8 GB. One holds all of my photographs and the other backs up my computer and the photography HD using Time Machine. Regardless.... after reading some of your reports I tried un-mounting my HD's before shut down and like magic... all shut down quickly. I hope Apple is working on a fix for this. I haven't had to ritualize my shut downs since my old PC-WIndows days! :-)

Right. I was hoping that the 11.2 upgrade would include a fix to this issue. It did not. Un-mounting my external backup drive prior to shutdown solves the immediate issue, but does not solve the problem. Note that my other external drive, used to store all of my photography, does not need to be un-mounted prior to shutdown. I would guess this has to do with Time Machine. It would be helpful to know if someone uses another backup system has the same problem.

It seems as if Apple will never admit they have a problem. This shut down problem with errors and rebooting has been going on for quite some time. Several of us have determined it had something to do with the external hard drive use for Time Machine. When we parked the backup drive first, the computer shut down properly.

Every time there is a system software update I try to shut down normally and the problem seems to persist. Recently I updated to 11.3 and them to 11.3.1 (today). The problem has gone away. I have shut down without error for 5 straight days now - without parking the external hard drive first. It seems as if this problem finally made it into the batch of fixes this time around.

I have had the same problem however if I eject the Time Machine, after it takes an inordinate amount of time to wake up, it shuts down fine. The TM seems to hang for too long for the MACOS to be able to shutdown.

How i resolved my issue with my external drives was to reinstall any driver software for them and since then no more issues.

I've been having this issue, too.

I have the Promise Pegasus R4i installed and a Pegasus3 R4 hooked up via Thunderbolt. I tried a lot of the suggestions I've seen in the communities about reinstalling drivers and ejecting the external enclosure before shutting down or restarting but still experience the problem of the Mac Pro crashing if I try to restart or shutdown.

The partial solution I've found is to close all application and log all users out and then shutdown or restart from the login screen. Not a 100% successful solution, but far better results than anything else, so far.