Google Search


Thursday, January 31, 2008

CentOS 5.1 kickstart lvm problems...

I have been messing around with the 5.1 kickstart for i386 for about 2 days now - as I'm not very good with python - as we need to kickstart PC-s with lvm support.

The error message states the following "An error occurred trying to format system/root_lv. This problem is serious, and the install cannot continue. Press to reboot your system."

And on tty5 (Alt + 5) another informative message "Could not stat /dev/system/root_lv --- No such file or directory. The device apparently does not exist; did you specify it correctly?"

It worked fine with the 5.0 tree, but when I wanted to kickstart with 5.1 I get an error that mkfs fails with /dev/system/root_lv and yes - there isn't a lvm path like that under the /dev.

After allot of debugging and messing around I found a workaround for it! It isn't easy nor is it for novice administrators so I would recommend just plain old install without the LVM support.

The problem is that the kickstart wont bring up lvm volumes before it tries to make a file system on them. Yes, it creates the physical volume, volume group and logical volumes, but it fails to activate them as the the LV-s are marked as created in the prep stages. This leaves us with a fully working LVM setup that is not activated and so the install crashes.

To fix the problem we need to hack the minstg2.img file in the repository. First make a backup of this file and copy it to a different folder. As I hacked it under Fedora 8 we need a package called "squashfs-tools" to unpack the image.

In the local folder run "unsquashfs minstg2.img" - this will create "squashfs-root" folder with the file system unpacked inside.

The problematic file is located "squashfs-root/usr/lib/anaconda" and the file is "".
On line 1753 there is "self.volumesCreated = 1" - this should be changed "self.volumesCreated = 0".

Warning - watch the spacing as python is very touchy with extra or missing spaces.

Save the file and "cd ../../../../" back to the beginning.

Now we need to create and new image and for that I strongly recommend creating an image with a different name.

To create the image run "mksquashfs squashfs-root test.img" and it will create the new image.

Warning - back up the original if you have not done it for now!!!

copy the test.img the the repository server and replace the original minstg2.img with the test.img.

This should do the trick and kickstarting PC-s with LVM should work now.

As I mentioned - this is an hack not a solution, so if you have automatic mirroring and the image gets rewritten with the old one copy the test.image back.

Also this bug could be fixed in the future so this hack will get obsoleted some time...

Update: Added exact error messages and my local mirror updated the minstg2.img from upstream, so I had to copy the test.img to the minstg2.img again...

Have fun.

Blogged with Flock