switch users --> black screen, no response [in 12.04]

[pete smout]

On 18/05/13 10:01, chris wrote:
> On Fri, 2013-05-17 at 22:21 -0700, rikona wrote:
>> Hello chris,
>>
>> Friday, May 17, 2013, 2:06:10 PM, chris wrote:
>
>>
>>> Try from the keyboard
>>> holding ctr alt syrq  the press in sequence rseiub
>>> This is the sysreq command for a clean shut down and reboot which should
>>> safely close the usb drives.
>>
>> WOW - that is a keeper! I didn't know about sysreq, but now see how
>> useful it can be.
>>
>>> has saved my bacon on more than one occasion
>>
>> I can believe that! Thanks much - that is a really useful piece of
>> info...
>>
>> --
>>
>>   rikona
>>
>>
> There are other sysreq commands, and I can suggest you can google for
> them
> Cheers Chris
>
>
>
Hi,

Apparently they have to be enabled!! see 
http://www.unixmen.com/use-magic-sysrq-combination-key-to-recover-from-a-frozen-system-in-linux-ubuntu/

good idea though seems to me that it should be enabled as default!

Pete