Michael DeHaan wrote:
Jennifer Cranfill wrote:
Last night I had to do the following procedure with Cobbler to boot a
remote server into rescue mode. I'm wondering if any one else thinks
it would be worthwhile to incorporate a rescue mode feature into
Cobbler's handling of pxe files? Or is there already one that I don't
know about?
Could we create "rescue" profiles automatically when we do imports?
It would just be a different profile ending in "-rescue" that would
just have "--kopts=rescue" added. Example "DistroName-i386-rescue".
The other thing we /might/ want to do is set up a kickstart template
for that profile (and assign it) that can be used to feed the rescue
image the media information, so you don't have to enter that in
manually.
Presumably that could all be done with modifications to action_import.py
We maintain a number of remote critical servers, and I think it would
be useful, especially as in the procedure below I had to be careful
that no one else rebooted the server or ran "cobbler sync" while I
was updating the pxe file. Also, it might be possible to automate
more of the rescue boot.
1) cobbler system edit --name=<sysname> --netboot-enabled=y; cobbler
sync
2) cd /tftpboot/pxelinux.cfg
3) Edit the file corresponding to the MAC of <sysname>. Take
everything out of the append line except the initrd and add "rescue",
like so:
append rescue initrd=/images/51x64/initrd.img
4) Reboot <sysname>
5) When the system boots, it will ask you for language and keyboard
and then it will ask you for the location of the *rescue* media. Just
give it the http to the normal install files for the distro matching
the initrd.
6) cobbler system edit --name=<sysname> --netboot-enabled=n; cobbler
sync
I took the idea from this Red Hat page:
http://www.redhatmagazine.com/2007/07/05/solutions-from-the-road-red-hat-enterprise-linux-rescue-mode-over-pxe-part-i/
If we do something like having a rescue profile, it's just:
cobbler system edit --name=server1 --profile=F-9-i386-rescue
--netboot-enabled=1
# fix system
cobbler system edit --name=server1 --profile=originalname
--netboot-enabled=0
The one thing that requires is knowing the proper rescue profile for
server1, so it's possible we could add a --rescueprofile= to the
system and also have a --rescuemode=1/0 like --netboot-enabled if you
think that's useful. That could be interesting.
That workflow might be like:
cobbler system edit --name=server1 --rescuemode (rescuemode could
actually set netboot-enabled to 1 for simplicity)
cobbler system edit --name =server1 --workingmode (this could set
netboot enabled back)
I'd be happy to help with the code, but not sure the right way to
architect it, perhaps some variant of netboot-enabled?
Sounds great!
Yeah I think the first step is making the rescue profiles when imports
are done, the second stage is probably something like
netboot-enabled (as above) if you like the workflow? Is that close?
I think I'd start taking a look at import for starters -- and if
that's not all that's needed we can work it from there.
Cool idea!
Thanks for your consideration!
--
Jennifer Cranfill
Systems Engineer
Sony Pictures Imageworks
cranfill@xxxxxxxxxxxxxx
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To clarify syntax a bit more and see if we're on the same page, how
about the following?
cobbler import --name=F9A --mirror=path
# automatically creates F9A-i386, F9A-i386-xen, F9A-i386-rescue as both
distros and profiles (action_import.py)
# automatically does the equivalent of "cobbler profile edit
--name=F9A-i386 --rescueprofile=F9A-i386-rescue"
Basically the above would allow any given profile to store the name of
/another/ profile that is used for rescue mode.
You may ask "why isn't rescue mode part of the distro", and the answer
here is that if it's a profile we can take advantage
of it also showing up in PXE menus automatically.
System syntax could also look like this:
cobbler system edit --name=F9A --rescuemode [implies --netboot-enabled=1]
cobbler system edit --name=F9A --workingmode [--netboot-enabled=1/0]
The commands --rescuemode would toggle netboot-enabled and temporarily
set up PXE to point to the rescue profile.
The command --workingmode would set it back, but at no time do you have
to remember what the proper rescue distro
is for a given system -- because it asks the profile for that info.
This would be something that would be really easy to incorporate into
the web interface as well -- as it would just be a couple of checkboxes.
That eventually involves also modifying files like action_sync.py and
modules/cli_system.py and item_system.py/item_profile.py -- though
nothing too invasive. (And I can help on this...)
--Michael
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