[Techtalk] I lost my filesystem

Robyn Manning rmanning at adam.com.au
Tue Apr 15 02:06:41 EST 2003

> How familiar are you with GRUB? GRUB reads filesystems and kernel executables, 
> rather than inflexibly restricting the user to disk geometry. It uses a 
> different partition numbering scheme than fdisk, GRUB starts from 0:
>  /dev/hda1
>  /dev/hda2
>  /dev/hda4
>  translates to
>  hd0,0
>  hd0,1
>  hd0,2
>  A second hard drive is hd1, and so forth..
> GRUB can find the boot partition and kernel. At boot, hit C to get to GRUB's 
> command line. To boot manually, you need 3 things: root, kernel, then the 
> 'boot' command. Use tab completion to find the root and kernel values. Type 
> the known value, in your case hd1, then keep hitting tab until something 
> happens:
> #use tab-completion
>  grub> root (hd1, 
> GRUB will respond something like this:
>  Possible partitions are:
>  Partition num: 0, Filesystem type is reiserfs, partition type 0x83
>  Partition num: 1, Filesystem type unknown, partition type 0x92
>  Partition num: 3, Filesystem type unknown, partition type 0x17
>  Partition num: 4, Filesystem type is ext2fs, partition type 0x83
> Enter the correct partition, yours is hdb2, so it looks like this:
> grub> root (hd1,1)
> GRUB will confirm:
>  Filesystem type is ext2fs, partition type 0x83
> Now find the kernel:
>  #use tab-completion
>  grub> kernel /boot/vmlinuz 
>  Possible files are: vmlinuz vmlinuz-2.4.19
> Enter vmlinuz-2.4.xx, whatever yours is, plus append the correct root line. 
> Notice the trickiness, on this line use fdisk-type values:
> grub> kernel /boot/vmlinuz-2.4.19 root=/dev/hdb2
> Enter the boot command:
>  grub> boot
> If you found the correct root partition and kernel, it will boot. Then edit 
> your GRUB boot menu, and there you are. Don't listen to people who tell you 
> to change your partition labels, they don't know what they are talking about.

I was saying in my message that if grub was like lilo there was stuff in
the boot record that needed changing.

Thanks for the link to the tutorial on grub. I tried it about 1 1/2
years ago without a tutorial and couldn't fathom it. I'm quite happy to
try new things it's just that I learned lilo first that's all.


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