Since installing Catalina yesterday, multiple crashes from userspace watchdog timeout

I've not had any issues with my VMs, although admittedly the only one I've had running in the past few days (constantly, fwiw) is my Docker vm which is using xhyve as the hypervisor, when I get through the work backlog the crashes gave me I'll risk firing up my Virtualbox and VMware Fusion vm's 😅

Memory usage increase is pretty standard behaviour; memory that isn't used is, literally, useless.

The kernel will page data in and out of memory to swap space under normal operations, so it's perfectly normal to see memory usage climb over the course of a day until the system begins to run low on free memory and the kernel needs to page some out.

This is especially common if you have a browser open with multiple tabs, all churning some (frequently inefficient) JavaScript which is making a ton of periodic calls to external services

I'd be very wary of jumping to conclusions around memory leaks in relation to this issue.

Yeah it's the wired memory that I'm concerned about. The only thing running on this machine is Virtualbox with a single Ubuntu VM. It's a Mac Mini that I run without a keyboard or monitor, so there are no browsers running, I don't use it as a desktop machine. I also have a second Mac Mini (a newer model), also with 16GB, that has been running for days, and the wired memory is still only a bit above 2GB.

I'm not sure if this is related or not, but it certainly seems like it points to a problem.

My update: have only seen one crash since 10.15.6. I have a 16" MBP that would crash like clockwork every time the display powered down. Nothing fixed it, not even (a now likely unnecessary) logic board swap. On 10.15.6 that has gone away. I have 64 gig of memory and 7.5 wired and the machine has been up for days. It's running app update, sys prefs, mail, several shells, safari with at least 8 windows and probably 50 tabs, chrome with 15 tabs, ichat, itunes, podcast, ACDsee photo, bbedit, serial tool, and a chat client. I haven't run VMWare since VMware won't run my VMs on this machine, not sure why that is yet. It can't open /dev/vmmon but I have allowed VMware in the security prefs.

I had not had a crash in 2 days until today when I was running VMware Fusion and then joined a MS Teams meeting. After about 15-20 mins into the Teams meetings, my MBP froze (could still hear the participants in Teams for about 1 minute) and crashed in a manner indicative of this problem. So excluding my "Virtual Machines" directory from Spotlight didn't fix this.

As long as I avoid running VMware Fusion at the same time as MS Teams, then 10.15.6 does not crash on me. I can run either one or the other, but not both simultaneously.

Unfortunately this don't worked.

I my case, i marked the onedrive folder, and also vmware virtual machines folder.

And i have 3 occurrences of kernel panic. I cannot pass one night without this error.. It's very sad.

Hi Guys,

Take a look on this explanation https://communities.vmware.com/message/2973190#2973190

It's exactly what happens to me.

Sound to be (no news) a bug in Catalina. For now i will try to monitor the real memory allocation for kernel_task and do some reboots to try to minimize that.

This may not be a one-size-fits-all situation, but virtualization definitely is a likely factor in my current issues (Macbook Pro - 2019 - 10.15.6). It does NOT only happen with external monitors (in my case), so I ruled out that factor early in my process. Oddly enough, I actually recently requested that my employer purchase VMWare Fusion for me because I was having such major issues with Virtualbox stability (and blamed VBox, not MacOS). I also now have VMWare Fusion running on my older MacBook Pro (2015 -- running 10.15.3 <-- important!!) and it runs 24/7 without any panics/reboots. I am definitely blocking any MacOS upgrades on my old one!! :)

Turning off Spotlight completely, along with unchecking power-saving options, DID seem to give me slight improvement with my newer MBPro, but maybe this is simply related to overall memory management, and how quickly MacOS needs to go into "panic mode".

Thanks for passing that link along -- definitely makes me think that this may be the ultimate root cause. Would be very interested to see if virtualization is a common denominator with other folks experiencing these constant kernel panics and watchdog timeouts on Catalina 10.15.6.

I highly recommend that you read the entire thread on the VMWare community forum posted earlier. It is clear that MacOS 10.15.6 has major issues with ANY virtualization software -- Virtualbox, VMWare, even Docker (all confirmed and reproduced by a very smart and helpful VMWare engineer). It has been officially reported to Apple (from VMWare engineering), but no timeline on an official fix date. Several people downgraded back to 10.15.5 and the panic/reboot issues were immediately resolved.

Again, I would be shocked if virtualization is the root cause for EVERYONE here, but I've seen a lot of people here in this thread mention running some sort of VM software on their Macs. So perhaps this is indeed the common thread for MOST of us. I am downloading the 10.15.5 installer now (to do an in-place downgrade), and will report back on my own results.

That's very useful thanks, any chance you could drop a link here please?

Despite using both of those regularly the only VM I've had running over the past several days is the xhyve (macOS native hypervisor forked from bhyve on FreeBSD, though you can use any of the others mentioned) one I have for Docker for Mac which hasn't caused any issues since I disabled Spotlight's ability to index Google Drive pseudo-locations.

Neither my VMware nor Virtualbox machines were running before I Mac’s that change but it’s a very useful piece of info nonetheless.

Memory (then panics, timeouts, reboots, etc.) issues caused by Catalina 10.15.6 and virtualization software (VMWare, VirtualBox, Docker):

VMWare Community Forum link provided earlier by user sergiorru (thanks!):

https://communities.vmware.com/message/2973190#2973190

Update:

I successfully downgraded my MBPro (2019 - 15") to 10.15.5 (in-place downgrade, nothing lost), and so far results look very positive. My fan stays quiet (unless I am compiling some code, etc. -- anything CPU intensive), and I've also been running VMWare Fusion (Linux VM) with no issues. Memory reports look good and reasonable in Activity Monitor.

Hopefully this will continue until an official fix is released!

Hi ktalley1015, glad to hear you found a solution that works for you!

Just thought I should sound a note of caution that this problem seems to manifest in a number of different ways for different people. My system NEVER crashed until the day I upgraded from 10.15.4 to 10.15.5, and then it crashed every single time I tried to wake it from sleep (either brief or overnight). Upgrading to 10.15.6 made the problem go away again and my system has not crashed since. I also have a 2019 MBP 15". I assumed the crashes were related to my operating in clamshell mode connected to an external monitor as many others in this thread have reported, but as I never did any testing in non-clamshell mode after the crashes started I suppose that I cannot definitively connect the crashes to clamshelling. I also use Fusion (Linux) but never had any crashes while actively using it (although I usually leave the VM running while sleeping).

These inconsistent triggering circumstances for various fellow-sufferers incline me to do no further minor-rev upgrades to my system now that I have it working again (for the time being at least).

Completely agree RogerDavis -- as I've mentioned several times in this thread, I DO NOT think this is a one-size-fits-all issue. It is clear, however, that 10.15.6 has a major memory leak issue with virtualization software (again, VMWare engineers have reproduced it). And in my case, this appears to be the primary "root cause", and downgrading to 10.15.5 seems (thus far) to have helped a great deal (solid proof will be if I can run a week or so without a panic/reboot).

Best of luck to people suffering with ANY issue with Catalina -- hopefully Apple will get their act together and give us STABILITY over bells & whistles. Or give us both... :)

Monkeyman8,

Here is what worked FOR ME (DISCLAIMER: My research has shown that this in-place 10.15.5 downgrade works for some, but not for others, so this is a definite "your mileage may vary" situation. Please do a backup before attempting any of this, and do your own research. DO NOT try it simply because it seems to have worked for me. I am only sharing what worked for me on my 2019 Macbook Pro (15") that was previously running Catalina 10.15.6. And I strongly believe MY primary issue was Catalina 10.15.6 and virtualization software -- the combination was causing memory leaks, which led to kernel panics, watchdog timeouts, and such. And my research showed that downgrading to 10.15.5 would likely resolve THIS issue until Apple can officially put out an o/s fix.

Thanks to a suggestion in the VMWare Community forum, I downloaded a free utility called MDS:

https://twocanoes.com/products/mac/mac-deploy-stick/

Install it, and when it launches, there is a Tools section in left-hand panel that has option called "Download macOS". Choose that, and after a couple of minutes, it comes back with a MacOS build list (I think this tool simply connects to Apple's API for build distribution). I chose 10.15.5 (Build 19F2200), and then clicked Download button. It will give you a "Busy" spinning wheel at the bottom (but nothing else), so if you want to actually track progress, go to the MDS "Window" menu (at top) and choose "Show Log". This will open a dialog window that will show you real time progress in a running log file. It took a while for mine to download & assemble (maybe 2-2.5 hours, but I have slow internet), but the end result was that it created a "sparseimage" file under "Users/Shared/macos_10155" subfolder. The log will show you the exact location of your file.

Double-click this sparseimage file (Install_macOS_10.15.5-19F2200.sparseimage) and it should open up a window with 2 folders -- "Applications" and "Library". Open up "Applications", and there should be an app ("Install macOS Catalina.app"). Double-click that app, and you should get the nice/pretty Catalina installer window. Start the installer, and after a few minutes, it will reboot and do the actual downgrade/install (mine took about 30 minutes total to complete).

After the install completed and my Macbook Pro restarted, I noticed that my touchbar was NOT visible (uh oh... what did I mess up?!), but after doing a bit of research, it appears that this is not so uncommon. I reset the SMC (https://osxdaily.com/2019/01/14/how-reset-smc-macbook-air-pro-2018-later/), and my touchbar was back as always -- no issues whatsoever since.

Again, this worked FOR ME, and all of my apps and data remained intact (and I'm now happily running 10.15.5 with no kernel panics and/or reboots -- at least for now!).