LHC@home

If I reboot a computer, any running LHC tasks screw up. Why? Why don't they continue where they left off like every other project? And what's with "Virtualbox still has active connections" when I try to reboot? It never goes away so I have to say "restart anyway". Connection to what? There's no data going through my internet router at this time.

If I reboot a computer, any running LHC tasks screw up. Why? Why don't they continue where they left off like every other project?

If you decide to run Virtual Machines on your computer from yourself or any project, you have to shutdown/close those VM's properly first before closing down the host machine.
Depending on the size of the VM and the speed of your disk, this needs time.
Advise to suspend in BOINC all VM-tasks 'Ready to start' first and then suspend (Leave applications in memory ticked off) the running ones one by one with at least 30 seconds interval.
By the way: ATLAS and CMS need an almost continuous internet connection, so when they restart properly after a longer suspend period, you're lucky.

And what's with "Virtualbox still has active connections" when I try to reboot? It never goes away so I have to say "restart anyway". Connection to what?

VBoxSVC still has a connection to the child processes like VBoxHeadless.exe, that is busy to write the state of a Virtual Machine to disk.

If I reboot a computer, any running LHC tasks screw up. Why? Why don't they continue where they left off like every other project?

If you decide to run Virtual Machines on your computer from yourself or any project, you have to shutdown/close those VM's properly first before closing down the host machine.

Hmph. Surely Boinc should pass the closedown message to virtualbox?

Depending on the size of the VM and the speed of your disk, this needs time.

But it still screws up even if I wait for all internet and disk access to stop.

Advise to suspend in BOINC all VM-tasks 'Ready to start' first and then suspend (Leave applications in memory ticked off) the running ones one by one with at least 30 seconds interval.

Thanks, I'll try that next time, then probably forget to retick!

By the way: ATLAS and CMS need an almost continuous internet connection, so when they restart properly after a longer suspend period, you're lucky.

From my logs, I see CMS sends a burst of about 120MB of data every so often, but it's not continuous. Boinc does sometimes switch between projects and leave them suspended in memory, but I've only ever had a computation error after a reboot.

And what's with "Virtualbox still has active connections" when I try to reboot? It never goes away so I have to say "restart anyway". Connection to what?

VBoxSVC still has a connection to the child processes like VBoxHeadless.exe, that is busy to write the state of a Virtual Machine to disk.

But the disk isn't in use and neither is the internet. It's doing nothing.