virtualbox.org

Host is a Mac OS X Server 10.9.4, running on an i7 Mac Mini, with 240GB SSD primary, 1TB rotational secondary, 16GB RAM.

Guest is a Debian Linux box, running Domoticz, and the device in question is a RFXtrx433, which is an FTDI USB <-> Serial device.

When the VM is in the foreground on MacOS X, everything works as expected - when the device is not foreground, the USB behaves sporadically, sometimes with a delay, sometimes not at all. The instant the VM is made foreground in the host, it behaves perfectly again.

Anything I can do to resolve (other than reverting to previous version of VirtualBox)? Or is a fix likely?

Happy to give more information if anyone can tell me what they would like to know...

AdamB wrote:Anything I can do to resolve (other than reverting to previous version of VirtualBox)?

Do you mean that it did work with a previous VirtualBox version, but it stopped working after you upgraded? What is the last version that it worked with?

Hi, yep, used to work perfectly.

Unfortunately, I'm not sure which version I upgraded from - there is a 4.3.10 installer kicking about in my Downloads folder, so thats pretty likely, but couldn't be 100% certain.

Thanks

Adam

I'm inclined to say that this has to be a host OS issue since it is the one that arranges priorities between applications (VirtualBox being one of them). So, with that in mind, two suggestions/questions:
- Did you upgrade your host lately?
- Try to revert back to 4.3.10 and see if that fixes the issue.

App Nap?

Have just disabled App Nap system wide (with defaults write NSGlobalDomain NSAppSleepDisabled -bool YES ) - so will see if that has any effect. You'd think when you install OS X Server it would be smart enough to realise that you don't want anything to sleep... =]

Re OS updates, probably - OS X tries really hard to do them...and sometimes when I'm not paying attention, I let it go ahead to get rid of the incessant dialogs...couldn't be certain though...

Will give it a while to see if disabling App Nap resolves it and update...

Adam