On 11/07/12 18:01, Mark Rogers wrote:
When I do regain access, is there any way I can make /proc/sys/kernel/trigger and /proc/sysrq-trigger writable by anyone other than root? Or do I need to make sure I'm always logged in as root until I find the root cause of this problem?
Typo there, I meant /proc/sys/kernel/sysrq
Anyway, yes I can make it writable by all users then write to it as a normal user.
So, for testing, rather than just echo b > /proc/sysrq-trigger (instant reboot, no sync etc) I tried the more graceful: echo r > /proc/sysrq-trigger # take control away from X, pointless as server is headless echo e > /proc/sysrq-trigger # SIGTERM to all processes echo i > /proc/sysrq-trigger # SIGKILL to all processes echo s > /proc/sysrq-trigger # Sync echo u > /proc/sysrq-trigger # Unmount echo b > /proc/sysrq-trigger # Reboot
Except that (doh!) after SIGTERM I lost access because (I assume) I'd just killed the SSH process. So once again I call guy on site to force a reboot....
However I think the principle is OK (unmounting the disk doesn't matter when it's gone anyway) so I just need to make sure that I have the right permissions on /proc/sys/kernel/sysrq - what's the best way to maintain this past a reboot?
None of this "solves" the core problem of-course....