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PC does not restart

Super Advisor

PC does not restart

Red Hat Enterprise Linux 4

When I send a "restart" or "shutdown -r now" command, the system init the restarting process. I can see all the messages of the services going down, but when it show the last message "Restarting System" it colds in this place. The hardware never restarts. I need to push the power button to turn off annd turn on, or push the reset button.

Is there anything I can do to enable the restart process trhough the operating system command?
Esteemed Contributor

Re: PC does not restart

Does the system shutdown, if you just send the request to shutdown? I know that older systems didn't have the auto-switch off function (soft power off). So even if you shutdown, you would have to press the power button to actually shut it down.

This can be ridiculous to think of these days, but it's just a doubt. :)
Honored Contributor

Re: PC does not restart

Normally RHEL4 does a reboot by making the keyboard controller pulse the reset signal on the motherboard.

There are some alternative reboot methods, selectable using kernel parameters at boot time. To select them, use an appropriate "reboot=". To make it permanent, add the parameter to your bootloader configuration (in RHEL4, usually the "kernel" line in /boot/grub/grub.conf).

The default method is equivalent to "reboot=hard". With some Dell models and HP laptops, you must use "reboot=bios" instead. Some kernel versions select this option automatically for those models.

With a SMP (multi-processor) kernel, you can also try "reboot=smp". This might useful only if your machine really has multiple CPUs or a multi-core CPU.

If you're interested, you might examine this particular bit of the Linux kernel source (file linux-/arch/i386/kernel/reboot.c). It contains the list of hardware models that are known to require "reboot=bios".

If "reboot=bios" fixes your problem and it's not yet automatic in the newest Linux kernels, you might want to report this problem to RedHat and/or Linux kernel developers, to have your hardware model added to the list.