Hard lock. Where the thing just locks at whatever it was doing and stops accepting input. Monitor continues to output video, but nothing is animated of course.
It's a video card freeze.
Are your video cards overclocked or undervolted?
If it happens again, try to ssh from another box if you can.
Have to hold down the power button to reset.
Didn't you try the magic sysrq keys (in Linux, of course)?
Sync first (S), then remount ro (U), then reboot (B).
http://en.wikipedia.org/wiki/Magic_SysRq_key--
Bye
I guess your post does reveal my vagueness.
First off I don't GPU mine, and while I definitely expect Linux's GPU drivers to be flaky, I've never had a problem on my Windows machine... ever. And even with knowing that Linux has crap for GPU drivers, I've never had a problem on that machine before either. But then both freeze soon after 2.7.4?
Either way, both cards are on stock settings and are not being used to mine either. I have only BFL devices. Again, not trying to point fingers but it does seem pretty coincidental.
About your magic keys, no I didn't do that. I know nothing about Linux, and maybe a little more about coding. Took C, C++, Java, VB back in college, never went anywhere with it. But I do know that code gets extremely complex, and when you have someone (like ck here) that loves to hack at his code, I try to bring any possibility of problem along in here because it's a rare opportunity to have such a close, ongoing communication between the main developer of -any- widely used software. This is because that even if your problem doesn't bring any bug kill to fruition, you never quite know how you're poking his brain with your words
..not that I don't think you know all of this. But some here might find this useful.
I will wait for both machines to freeze in a similar manner, and if it happens go back to 2.6.6 and wait for another freeze.