I just have installed Debian 4 through Internet. But after successfull installation finish, I rebooted as said, but Debien hangs on booting.

GEOMETRY (HD0)
drive 0x80: C/H/S = 1023/255/63, .....
Partition num: 0, Filesystem type is ext2fs, partition type 0x83
Partition num: 4, Filesystem type unknown, partition type 0x8e

LAST THREE LINES WHEN GOT HANG:
VFS: Cannot open root device "mapper/debian-root" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Somebody please help. And thanking you.