Instant Crash Rendering Mac OS

[THExDUKE]

Hey community,

yesterday I have updated my workstation (Mac Pro 2019 / 2.5 GHZ 28-Core Xeon W / 256 GB Ram / AMD Pro Vega II 32GB) from MacOS 11.2.1 to 11.2.3. From that on I was unable to render in viewport. Maya was instantly crashing when I tried IPR either in viewport or FB. Even Rendering in FB crashed the system instantly. Batch rendering worked for some reason. I was on Maya 20.4 and Vray 5 hotfix 1 and updated to hotfix 2, even installed Vray Next again with no success!

My admin then came up with the solution he found for a similar problem with same workstation specs on his side but with C4D and Vray for C4D: he set the following command for his machine and it seemed that this worked for him: sudo launchctl limit maxfiles 8192 200000 !! Same command made my workstation render again as if nothing happened before.
Unfortunately this workaround needs to be done after every restart of the machine.

Hope you guys find a fix soon, because this really sucks and out of the blue I have issues.

BR

Duke

[sirio76]

This Vray for Cinema4D user had the same issue, solved with an hotfix update but it was on Catalina, don't know if this helps but you are not alone:
https://forums.chaosgroup.com/forum/...28-cores/page2

[THExDUKE]

This Vray for Cinema4D user had the same issue, solved with an hotfix update but it was on Catalina, don't know if this helps but you are not alone:
https://forums.chaosgroup.com/forum/...28-cores/page2

Hotfix for the C4D hasn´t helped us. Our only way currently for both Maya and c4d is the stupid command

[deyan.hadzhiev]

Hi THExDUKE, the issue is related to the default max files limit on newer MacOS systems, which seems to be pretty low - 256. Since this is a file limit, it means any open files by the process potentially fill the limit. Again - since this is an OS limitation there isn't much we can do from the process itself and the only good solution is to raise that limit with the mentioned command.

Unfortunately this workaround needs to be done after every restart of the machine.

There is a way to automate this to be executed on each OS boot, by adding a plist with the command description in the system launch daemons, located in /Library/LaunchDaemons. I'll attach an example plist file, that has to be copied there and after it is copied you have to load it with launchctl, with this command:

sudo launchctl load -w /Library/LaunchDaemons/limit.maxfiles.plist

Note that the file must be owned by root:wheel and must have the following permissions "-rw-r–r–". This can be achieved by the following two commands:

sudo chown root:wheel /Library/LaunchDaemons/limit.maxfiles.plist
sudo chmod 0644 /Library/LaunchDaemons/limit.maxfiles.plist

[THExDUKE]

Hi THExDUKE, the issue is related to the default max files limit on newer MacOS systems, which seems to be pretty low - 256. Since this is a file limit, it means any open files by the process potentially fill the limit. Again - since this is an OS limitation there isn't much we can do from the process itself and the only good solution is to raise that limit with the mentioned command.


There is a way to automate this to be executed on each OS boot, by adding a plist with the command description in the system launch daemons, located in /Library/LaunchDaemons. I'll attach an example plist file, that has to be copied there and after it is copied you have to load it with launchctl, with this command:

sudo launchctl load -w /Library/LaunchDaemons/limit.maxfiles.plist

Note that the file must be owned by root:wheel and must have the following permissions "-rw-r–r–". This can be achieved by the following two commands:

sudo chown root:wheel /Library/LaunchDaemons/limit.maxfiles.plist
sudo chmod 0644 /Library/LaunchDaemons/limit.maxfiles.plist

Thank you Deyan for your comment. The strange thing is, that it has worked fine since I have this Machine. This phenomena occured just after this update. Really bizarre. And I don´t understand the relation btw. between the open files and the rendering itself.

[deyan.hadzhiev]

Without venturing too much into detail - the relation is caused by the Qt library (used both by V-Ray for the VFB and Maya itself for their GUI). In Qt each thread opens a pipe for communication (and pipes use file descriptors), so when all available descriptors are used, if it happens that Qt tries to create a new thread, it fails and this leads to the crash.

The strange thing is, that it has worked fine since I have this Machine. This phenomena occured just after this update.

There may be various reasons why the upgrade may have caused this. The file limit may have been decreased, or something caused more file descriptors to be used. It is hard to pinpoint the exact culprit.

[THExDUKE]

Without venturing too much into detail - the relation is caused by the Qt library (used both by V-Ray for the VFB and Maya itself for their GUI). In Qt each thread opens a pipe for communication (and pipes use file descriptors), so when all available descriptors are used, if it happens that Qt tries to create a new thread, it fails and this leads to the crash.


There may be various reasons why the upgrade may have caused this. The file limit may have been decreased, or something caused more file descriptors to be used. It is hard to pinpoint the exact culprit.

Thanks for the short explanation. I forwarded the launcher daemon script to my IT guy and he said "excellent support from that guys" We installed it and for now live with that workaround. Thank you.