Boot failure if grub default OS changes

[joneall]

Don't know quite what to title this one.

Since I left my computer off for a while without a keyboard, it has developed a strange sympton.

If I boot by picking my /dev/sdb1 system as the default OS in grub and booting that, it hangs with a big blue Kubuntu page. If I connect via the recovery mode of the same system, I can connect. So I change the grub default OS by modifying only GRUB_DEFAULT to a value of 4 (maybe any non-zero value would work), do an update-grub, then reboot and select manually the /dev/sdb1 system (not the recovery mode), it shows me the same screen, but then changes to the normal login screen and everything works.

If I put the default system back on /dev/sdb1, it hangs again.

This is Lucid with Grub2.

One other thing. The rescue disk with rescuecd does not boot the system: I have to use the alternate rescuecd. I have no idea what the difference may be.

What in the world could this be due to. Has grub stopped liking the default OS somehow?

[Guest]

Re: Boot failure if grub default OS changes

I am having similar issues with my grub2 boot loader that it boots into the grub prompt. This happened right after updating to kernel 2.6.32-22.

I copied down the instructions of what to do in this case to get into linux (set root=(hdx,x; linux /boot/vmlinuz... initrd /boot/initrd.... boot) which starts a load but eventually times out saying it cannot find root or something like that.

I also tried to repair a broken system from the kubuntu live dvd and tried to manually install grub from booted linux on the dvd. I have re-installed Kubuntu several times. I will be checking if its an issue involving the SATA cables coming loose or an HD overheating because my computer had that happen before.

I have Linux installed on my 2nd HD, first partition (HD1,1) or SDB1. with Windows 7 on the First Hard Drive, First Partition. My computer uses a AMD64 Duel Core Processor. 2GB ram. Both HDs are SATA.

You all know this is inconvenient since locks anyone out from any operating system and therefore have no access to the internet unless they have another computer. Not everyone is a grub geek and know about the Ubuntu Grub 2 Wiki when they first try to use Linux.