GRUB Legacy - unable to determine the file system type
 

I had only Arch on an HDD.
sda2 was "/".
Now it's with Windows XP and sda2 is not a root any more but a container partition wich has sda{5,6,7} in it. I configured the dual boot and it works. It finds Arch and boots it, but not completely. Stops after some time and says: unable to determine the file system type of /dev/sda2. FSTAB is configured, sda{5,6,7} are on their places. So I can't boot Arch. XP boots correctly. What do I do with this error?

Also it says: try adding rootfstype=your_filesystem_type to kernel command line.
What type is sda2 then? And what should I add exactly?

This may help you.

http://www.linux.com/archive/feed/57240

Ususally windows takes sda1 and sda2. I would use gparted and see what partitions are there and what fs type. Also if your grub is in root partition of arch linux you can change boot flag.

Gparted-live-cd
http://gparted.sourceforge.net/download.php

Looks like the problem was in /boot/grub/menu.lst. In Arch section there was sda2 instead of sda5.

go to the GRUB command prompt.

Example:

grub> root (sda, // Type upto "sda," and press tab you can see the available boot block tag showing in the list. There you can find the file system type. From there you can identify whether your windows file system tag is showing or not. If you didn't see the NTFS file system tag, you have to rebuild the grub.

83 for Linux partition
8e for Linux LVM partition
7 for NTFS partition.

Best regards