forcing a reboot

forcing a reboot

[urgrue]

is there a way to force an instant reboot? in some cases "reboot" 
doesnt work, as it seems to do many things before actually initiating a 
phsyical reset, like shutting down processes. ive now run into the 
situation a few times where zombie processes or module problems can 
prevent "reboot" from completing its task.

Re: forcing a reboot

[Adrian C.]

You could try a killall -9 zombie_process_name before reboot. man
reboot has no force reboot option that i can see.

--Adrian.

On Fri, 22 Oct 2004 13:29:23 +0300, urgrue <urgrue@tumsan.fi> wrote:
> is there a way to force an instant reboot? in some cases "reboot"
> doesnt work, as it seems to do many things before actually initiating a
> phsyical reset, like shutting down processes. ive now run into the
> situation a few times where zombie processes or module problems can
> prevent "reboot" from completing its task.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
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>

Re: forcing a reboot

[Andreas Unterkircher]

if you really nead a reboot and you have sysrq (Magic Sysrq Key in the
Menu Kernel hacking) enabled, you can use 

    echo b > /proc/sysrq-trigger 

to reboot - if your system is still alive then you can try the
combination

    ALT+"Print Screen"

to get the Sysrq-Menu in the console and then press the key as shown on
the oncoming menu.

more information you could find in the file sysrq.txt in the
documentation directory of the linux kernel sources.

hope this helps you.

andi


Am Freitag, den 22.10.2004, 13:45 +0300 schrieb Adrian C.: 
> You could try a killall -9 zombie_process_name before reboot. man
> reboot has no force reboot option that i can see.
> 
> --Adrian.
> 
> On Fri, 22 Oct 2004 13:29:23 +0300, urgrue <urgrue@tumsan.fi> wrote:
> > is there a way to force an instant reboot? in some cases "reboot"
> > doesnt work, as it seems to do many things before actually initiating a
> > phsyical reset, like shutting down processes. ive now run into the
> > situation a few times where zombie processes or module problems can
> > prevent "reboot" from completing its task.
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: forcing a reboot

[chuck gelm]

Andreas Unterkircher wrote:

>if you really nead a reboot and you have sysrq (Magic Sysrq Key in the
>Menu Kernel hacking) enabled, you can use 
>
>    echo b > /proc/sysrq-trigger 
>
>to reboot - if your system is still alive then you can try the
>combination
>
>    ALT+"Print Screen"
>
>to get the Sysrq-Menu in the console and then press the key as shown on
>the oncoming menu.
>
>more information you could find in the file sysrq.txt in the
>documentation directory of the linux kernel sources.
>
>hope this helps you.
>
>andi
>
>
>Am Freitag, den 22.10.2004, 13:45 +0300 schrieb Adrian C.: 
>  
>
>>You could try a killall -9 zombie_process_name before reboot. man
>>reboot has no force reboot option that i can see.
>>
>>--Adrian.
>>
>>On Fri, 22 Oct 2004 13:29:23 +0300, urgrue <urgrue@tumsan.fi> wrote:
>>    
>>
>>>is there a way to force an instant reboot? in some cases "reboot"
>>>doesnt work, as it seems to do many things before actually initiating a
>>>phsyical reset, like shutting down processes. ive now run into the
>>>situation a few times where zombie processes or module problems can
>>>prevent "reboot" from completing its task.
>>>      
>>>
I do not have a 'sysrq'.
I am using Slackware v9.1, kernel 2.4.22.
Is 'sysrq (Magic Sysrq Key in the Menu Kernel hacking)'
 distribution specific.
grep -i sysrq /usr/src/linux/.config returns 'null'.
?

 Anyhow, I use
'halt'
 to shut my systems down in a hurry.

Regards, Chuck

Re: forcing a reboot

[Kevin J. Cummings]

chuck gelm wrote:
> I do not have a 'sysrq'.

It is usually:  ALT + Print Scrn

> I am using Slackware v9.1, kernel 2.4.22.
> Is 'sysrq (Magic Sysrq Key in the Menu Kernel hacking)'
> distribution specific.
> grep -i sysrq /usr/src/linux/.config returns 'null'.
> ?
> 
> Anyhow, I use
> 'halt'
> to shut my systems down in a hurry.



-- 
Kevin J. Cummings
kjchome@rcn.com
cummings@kjchome.homeip.net
cummings@kjc386.framingham.ma.us

Re: forcing a reboot

[chuck gelm]

Kevin J. Cummings wrote:

> chuck gelm wrote:
>
>> I do not have a 'sysrq'.
>
>
> It is usually:  ALT + Print Scrn
>
>> I am using Slackware v9.1, kernel 2.4.22.
>> Is 'sysrq (Magic Sysrq Key in the Menu Kernel hacking)'
>> distribution specific.
>> grep -i sysrq /usr/src/linux/.config returns 'null'.
>> ?
>>
>> Anyhow, I use
>> 'halt'
>> to shut my systems down in a hurry. 
>
Hi, Kevin:

"ALT + Print Screen"

 does nothing on three of my linux o/s computers.

Chuck

Re: forcing a reboot

[Glynn Clements]

chuck gelm wrote:

> >> I do not have a 'sysrq'.
> >
> >
> > It is usually:  ALT + Print Scrn
> >
> >> I am using Slackware v9.1, kernel 2.4.22.
> >> Is 'sysrq (Magic Sysrq Key in the Menu Kernel hacking)'
> >> distribution specific.
> >> grep -i sysrq /usr/src/linux/.config returns 'null'.
> >> ?
> >>
> >> Anyhow, I use
> >> 'halt'
> >> to shut my systems down in a hurry. 
> >
> Hi, Kevin:
> 
> "ALT + Print Screen"
> 
>  does nothing on three of my linux o/s computers.

1. You need to enable the feature with e.g.:

	echo 1 > /proc/sys/kernel/sysrq

If that file doesn't exist, the kernel was built without SysRq support
([CONFIG_]MAGIC_SYSRQ).

2. You need to use Alt+PrtSc+<key>, where <key> is one of those listed
in /usr/src/linux/Documentation/sysrq.txt:

'r'     - Turns off keyboard raw mode and sets it to XLATE.

'k'     - Secure Access Key (SAK) Kills all programs on the current virtual
          console. NOTE: See important comments below in SAK section.

'b'     - Will immediately reboot the system without syncing or unmounting
          your disks.

'o'     - Will shut your system off (if configured and supported).

's'     - Will attempt to sync all mounted filesystems.

'u'     - Will attempt to remount all mounted filesystems read-only.

'p'     - Will dump the current registers and flags to your console.

't'     - Will dump a list of current tasks and their information to your
          console.

'm'     - Will dump current memory info to your console.

'v'	- Dumps Voyager SMP processor info to your console.

'0'-'9' - Sets the console log level, controlling which kernel messages
          will be printed to your console. ('0', for example would make
          it so that only emergency messages like PANICs or OOPSes would
          make it to your console.)

'e'     - Send a SIGTERM to all processes, except for init.

'i'     - Send a SIGKILL to all processes, except for init.

'l'     - Send a SIGKILL to all processes, INCLUDING init. (Your system
          will be non-functional after this.)

'h'     - Will display help ( actually any other key than those listed
          above will display help. but 'h' is easy to remember :-)

-- 
Glynn Clements <glynn@gclements.plus.com>

Re: forcing a reboot

[Thornton Prime]

> "ALT + Print Screen"
> 
>  does nothing on three of my linux o/s computers.

If it is not built into your kernel, it won't work.

If it is, you need to enable it with a sysctl -w kernel.sysrq=1.

You then need to use a magic key combination of
[ALT]+[PrintScrn]+<KEY>, where <KEY> is one of 0-8beikmoprstu. Use 'h'
to get help.

thornton

Quota setting

[Edward Parrilla]

Hi all,
I have defined the following partition:

/dev/hdb3               /mnt/newfs              devpts defaults,usrquota
0 0

And when running the quotacheck gives me this message

/sbin/quotacheck -uagv
quotacheck: Can't find filesystem to check or filesystem not mounted
with quota option.

How do I create the quota.user for that partition?

Thanks in advance for your advice
Regards
Ed

Re: forcing a reboot

[Thornton Prime]

urgrue wrote:
> is there a way to force an instant reboot? in some cases "reboot" doesnt 
> work, as it seems to do many things before actually initiating a 
> phsyical reset, like shutting down processes. ive now run into the 
> situation a few times where zombie processes or module problems can 
> prevent "reboot" from completing its task.

For "extreme" rebooting, check out the kernel sysctl interface. You can send commands via keyboard, 
serial, or cat > /proc/sysctl. Command include forced reboot, killall, killall (minus init), dump, etc.

thornton