OpenVZ Kernel Panic

[RobinVossen]

Ok, I have a Fresh Gentoo install.
My Kernel works fine It runs grub everything is fine.
Well this is for testing OpenVZ. Since I was out of SpareBoxes I had to use my Work Terminal (a Compaq Laptop of some kind that runs Windows XP (Im not allowed to change that)) so I started up innotek Virtual Box in WinXP Pro. and I Installed Gentoo. Everything works fine (exept that atkbd.c keeps spamming in the terminal) So I emerged openvz. I used the Guide: Gentoo Linux Documentation -- Gentoo OpenVZ Howto
but when I had to boot the OpenVZ kernel I got Kernel Panic.
The Terminal says:

VFS: Cannot open root device "hda1" or unknwon-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)

So I thought, ok this is a grub error.
So here is my grub:

default 0
timeout 10
title=Gentoo
root(hd0,0)
kernel /boot/kernel root=/dev/hda1
title=OpenVZ
root(hd0,0)
kernel /boot/kernel-openvz root=/dev/hda1

Thats the same.. so I dont see the error there.
So I checked the kernels.
and yea they both can read the format that the hda1 is partitioned in.
(Keep in mind that this is a test box so I didnt do good partitioning its hda -> / and hdb -> swap)

Anyhow, I dont really see a error.
So can somebody tell me what the kernel error makes?
Cheers,
Robin

[aliov]

VFS: Cannot open root device "hda1" or unknwon-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)

this is is a typical error ,when you don't have a initrd to load the modules before mounting the root filesystem , the other kernel can load them because it was compiled against all the necessary modules as built in , and specially the fs modules , it's not the case for the openvz kernel wish have been compiled the fs as modules , so in order to run the second kernel you have to make the initrd file with at least the specific filesystem that you are using , i never used gentoo , but usually this can be done (in Slackware )

mkinitrd -c -k 2.6.21.5 -m reiserfs:intelfb

i believe it'll be similar in gentoo you can google it , after that you have to add the entry in the grub menu.lst

intrd /boot/initrd-xxxxx

another possible solution is to recompile the kernel with fs built in (specially your root fs and ext2 ) .

Hope this helps .

Regards.

[RobinVossen]

Ok, well I dont get the command to work.
But I found a nice Debian Install Guide so I guess Ill follow that

[aliov]

In debian it's mkinitramfs , but usually you can regenerated like :

dpkg-reconfigure linux-image-$(uname -r)

Regards.