[ubuntu-za] Random Freezes

[Trevor Hughes]

On Tue, Dec 21, 2010 at 3:53 PM, David Nel <david.uberdiablo at gmail.com> wrote:
> My system would also go in to a dead freeze where I could not access any
> shortcut commands to gain access to the console or even force a reboot. I've
> now installed the latest kernel within the maverick release and will have to
> see how it goes. Hopefully it doesn't give anymore freezes.

Are you talking about the magic keys Alt-SysReq R-E-I-S-U-B

SysReq is the same key as PrtScn!

B boots and the others reset and sync and do other nice stuff

Quite often those keys will work even when your system seems frozen
solid. If it responds to these keys it was not completely dead!

from wikipedia

unRaw      (take control of keyboard back from X),
 tErminate (send SIGTERM to all processes, allowing them to terminate
gracefully),
 kIll      (send SIGKILL to all processes, forcing them to terminate
immediately),
  Sync     (flush data to disk),
  Unmount  (remount all filesystems read-only),
reBoot.

This can prevent a fsck being required on reboot and gives some
programs a chance to save emergency backups of unsaved work.

In practice, each command may require a few seconds to complete,
especially if feedback is unavailable from the screen due to a freeze
or display corruption. For example, sending SIGKILL to processes which
have not yet finished terminating can cause data loss.

Trev