On macOS Catalina since 10.15.6, I’ve been fighting kernel panics when running VMs in VMware Fusion. Typically, I’d be running the GNS3 VM, and this would cause the system to hard crash after a few hours. Supposedly, a supplemental update to macOS 10.15.6 fixed this issue, but not for me. Nor did the upgrade to 10.15.7. That meant I’d been unable to get labs setup and leave them running for more than a few hours without the system blowing up. Pretty annoying if you’re in the middle of a larger lab and need to let it go overnight so you can, I dunno, sleep.
Catalina’s successor Big Sur aka macOS 11 has been out for some time, but I’d been putting the upgrade off…because I know better. Major version upgrades to macOS are usually traumatic in the early days, especially for folks like me that do a lot of audio recording and processing. So, I put off Big Sur, living with the Catalina kernel panics…until yesterday.
The Big Move To Big Sur
I’d finally had enough of the panics, so I did some crawling around vendor sites who make the the audio gear I rely on. All of them gave a (qualified) thumbs up to macOS 11, so I decided to take the plunge on my iMac Retina 5K, 27-inch, 2020–the last of the Intel iMacs. I followed the typical Apple upgrade process, and it took as long as these things usually do–perhaps an hour or so. I didn’t time it, but if you’re a Mac owner, you know the process. Download the code. Shutdown all the things. Restart. Read the lies about estimated time the progress bar tells you. Restart again. Do a dance. Sacrifice a goat. Etc.
Eventually, you back to the familiar login prompt, type your password, wait for the Bluetooth keyboard to connect, delete whatever few characters made it through while the keyboard was waking up, re-type your password, close your eyes, sigh heavily, open your eyes, and behold the fresh UI Apple has decided is best for you. Oh. And take the inevitable “Tour”, Apple’s release notes for normies. (Confession. I usually take the Tour, but only if no one else is around to witness my shame as I allow myself to be indoctrinated by Uncle Tim.)
As my iMac has a T2 security chip, I ran into a known issue where my valid password on an admin-equivalent account was not honored while trying to tweak System Preferences, forcing me to reset the SMC. I don’t remember the procedure exactly. There was the holding down of power buttons for several seconds, kicking cats, and yelling out of a window while shirtless, if I recall correctly. But aside from that, upgrade drama was otherwise minimal.
Apple’s Native Hypervisor APIs
Onto VMware Fusion 12.1.0. I am using the paid, full version, and not the free Player. I’m not sure how the experiences might differ between the two. But I initially ran into slow VM performance until I disabled side channel mitigations per VM. After that, VMs were usable for me, except for a Win10 VM with display problems. All of my Linux VMs, including the GNS3 VM, were running fine.
Not only have they been running fine, but the system seems stable. No kernel panics since the move to Big Sur 11.1. This isn’t entirely shocking, since Apple has re-architected the virtualization subsystem. VMware in the Fusion Blog reports the following.
Big Sur brings with it some really big visual changes, but also major changes under the hood. For instance, Apple has been progressively deprecating 3rd party Kernel Extensions or “kexts” which Fusion needs to run VMs and containers. In order to continue to operate in this model, we’ve re-architected our hypervisor stack to leverage Apple’s native hypervisor APIs, allowing us to run VMs without any kernel extensions.
Even with minor caveats, I seem to be in a better place with macOS 11.1 Big Sur versus macOS 10.15.7 Catalina. Big Sur is not a flawless experience for me yet, but I have hope it will become so as software makers have time to adjust to all of Apple’s changes. And I’ll take being able to run GNS3 labs without kernel panics as a big win.
What’s Next? Maybe CML 2.1.1…
I am hoping to get Cisco Modeling Labs 2.1.1 fired up on this new machine, although I think there’s a good chance CML won’t work right on Big Sur. Cisco’s documentation is a bit sparse, but the release notes for CML 2.1 say to not go to Big Sur.
But then in the 2.1.1 release notes, the supposed issue from CML 2.1 was fixed, although Cisco doesn’t say to charge ahead with a Big Sur upgrade. So…meh. It’s a roll of the dice based on that, but since I don’t have anything invested in CML as yet, I’ve got nothing to lose. I’ll be your guinea pig.
Whether I have (or do not have) any luck with CML 2.1.1 on macOS 11.1 with VMware Fusion 12.1.0 hosting the VM, I’ll do a separate write up.
For More Information
VM Ware Fusion potentially causes macOS 10.15.6 to crash – VMware Communities
If you can’t unlock settings in System Preferences – Apple Support
Virtual Machines with side channel mitigations enabled may exhibit performance degradation (79832) – VMware KBase
Fusion 12 w/ Big Sur Display Flicker – VMware Communities
Ready for Testing: Updated Tech Preview with Big Sur Support – VMware Fusion Blog
