Remote Rescue - PXE, SSH, and a remote console?

[Todd Denniston]

Ryan Wilson wrote, On 10/30/2008 04:16 PM:
> Hi,
> 
> I've got a Linux server at my parent's house. It had some hardware troubles
> and I shipped them a new computer and asked them to move the hard drive
> over. That worked out great, except now Fedora 8 won't boot. I think I know
> why (I think I need to rebuild my initrd), but how can I do that from
> remote? 
<SNIP>
> 
> Is there a way to have the kernel reboot the system automatically if it
> can't mount the root filesystem? I'm not 100% sure where the system is
> hanging, but I think nash gives up when it can't find the filesystem and
> just hangs. Can I specify that the kernel reboot on panic on the command
> line? My setting in /etc/sysctl.conf doesn't get run because the root
> filesystem isn't mounted yet!
> 
http://www.google.com/search?hl=en&q=kernel+reboot+on+panic&btnG=Google+Search&aq=f&oq=
http://www.cyberciti.biz/tips/reboot-linux-box-after-a-kernel-panic.html
says you can
"add panic=10 to the kernel command line, it will have exactly the same effect."
as setting kernel.panic = 10 in /etc/sysctl.conf

> Is there something I can use to trigger remote reboots? Like a wake-on-lan
> packet that reboots the system when hung?
> 
> Is there a linux distro (preferably Fedora or one of its variants) that I
> can boot a rescue session from using PXE? I'd like to build a setup with
> grub, pxelinux, etc... (if possible) where it boots into the main OS and on
> reboot, it will switch back-and-forth to a rescue distro. 
<SNIP>

https://www.redhat.com/archives/fedora-test-list/2008-September/msg00353.html
https://bugzilla.redhat.com/show_bug.cgi?id=159287
suggests that a rescue mode image (initrd) might be setup as a grub target.
Perhaps you should add to that bug, with some ideas from your experience.

And if you are adventuresome you might try this idea from the same thread:
https://www.redhat.com/archives/fedora-test-list/2008-September/msg00380.html

Still seems a bit scary having a machine up on the net with the non protected 
rescue environment. I hope you get it fixed quickly.


Of course with your situation, it MIGHT be easier to have them express the 
hard drive to you and work on it locally. :)

-- 
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter