Need to reinstall grub - how to boot Proxmox bare metal install CD into rescue mode?

[luminarycrush]

So this is frustrating. I had a power outage and the Proxmox 2.0RC1 system I'm using will no longer boot the hard disk. I want to try to reinstall grub to the boot sector.

I can't see how to boot the Proxmox bare metal installer into rescue mode, so I tried an Ubuntu disk I had laying around. I can see all my filesystems, I can start LVM and mount things.. but I can't chroot and run grub-install because the binaries mismatch. I tried a Debian 6.04 install CD, go into rescue mode.. and I can't mount my filesystems for some reason. This gets really weird..... the LVs show they are active, and they *sometimes* mount but when I list the mount points I get "I/O error". Or... they refuse to mount, saying something about ext2 option not supported (40) ext3 option not supported (40) ext4 journal not found. So, Debian rescue is useless up to this point.

I've also tried Trinity rescue CD - which again lets me mount the LVs and see files/copy them out... but I can't run grub-install. (also weird... I copied out one VM I had installed, but two others I used LVM storage I believe and they seem to have disappeared... not sure, maybe I need the Proxmox kernel running to see them.)

I've searched here and can't see how to do it from the Proxmox CD. At the boot prompt I've tried "rescue" and "rescue/enable=true" and I just get the installer. At one point I can get an Xwindow right-click menu which has "Terminal emulator" option but I click on it and nothing happens... then the installer starts and I lose all control of the graphical session outside of the scripted install.

Is rescue mode not available in the installer CD? If it's not, how do I get grub reinstalled?

 

[marotori]

Re: Need to reinstall grub - how to boot Proxmox bare metal install CD into rescue mo

You should in theory be able to use the rescue mode from a debian squeeze system?

Once in at the CLI... chroot to the correct root filesystem.. run update-grub

Never tried it.. but thats what I would start on

 

[tom]

Re: Need to reinstall grub - how to boot Proxmox bare metal install CD into rescue mo

see http://pve.proxmox.com/wiki/Debugging_Installation

 

[luminarycrush]

Re: Need to reinstall grub - how to boot Proxmox bare metal install CD into rescue mo

I mentioned I tried that - Debian 6.04 (squeeze) can't mount the filesystems for some reason - dmesg shows the error when trying to mount the various PVE LVMs with an 'unsupported options' message. Then it says 'can't find journal file'. It appears that the generic Debian rescue mode is missing something.

Strangely, Ubuntu and the Trinity rescue live CDs can mount the filesystems just fine & I can copy files out - but I cannot "chroot" and thus re-install GRUB.

 

[udo]

Re: Need to reinstall grub - how to boot Proxmox bare metal install CD into rescue mo

I mentioned I tried that - Debian 6.04 (squeeze) can't mount the filesystems for some reason - dmesg shows the error when trying to mount the various PVE LVMs with an 'unsupported options' message. Then it says 'can't find journal file'. It appears that the generic Debian rescue mode is missing something.

Strangely, Ubuntu and the Trinity rescue live CDs can mount the filesystems just fine & I can copy files out - but I cannot "chroot" and thus re-install GRUB.

Hi,
you can try to boot an grml64 live-cd and then use chroot (must use bash instead of zsh, but should work). Otherwise you can also use grubinstall without chroot...

Udo