[CentOS] system unresponsive

Thu May 23 00:50:10 UTC 2019
Gordon Messmer <gordon.messmer at gmail.com>

On 5/22/19 6:57 AM, Scott Silverman wrote:
> In the past I've found that the console may have blanked (due to time) and
> when the system locked up/hung it won't unblank. Booting with
> "consoleblank=0" on the kernel command line will ensure that whatever is
> printed to the console (oops, panic, etc) will be there for you to see when
> you connect.

I would definitely start here.  If the system locks and there's no oops 
printed to the screen, then you almost certainly have a hardware issue.  
If there *is* an oops printed, you might still have a hardware issue, 
but the oops will probably give you some direction on tracking it down.

At some point, you'll probably want to schedule as many hours of down 
time as possible and run memtest86+

> I've had intermittent success in that type of situation with the SysRq
> key(s), seehttps://en.wikipedia.org/wiki/Magic_SysRq_key  .

If the console isn't coming back on keyboard activity, then the system 
is probably hard-locked, and sysrq keys aren't going to work.  Probably.