# xen kernel panic [solved]

## Hadriel

hey. i read the tutorial on gentoo-wiki, but i fail at booting the xen kernel. message is: 

"VFS: Cannot open root device "sda3", Please append a correct "root=" boot option

Kernel panic: VFS: Unable to mount root fs on sda3"

in a xen tutorial in this forum () i found out that i have to set

CONFIG_BLK_DEV_IDEDISK y

CONFIG_BLK_DEV_IDEGENERIC y

CONFIG_PARTITION_ADVANCED y 

in the kernel. I did this, but still the same error message.

sda3 IS my root partition, and the grub.conf seems to be correct.

so if anyone has infos, please tell me  :Wink: Last edited by Hadriel on Mon Jul 24, 2006 8:11 pm; edited 1 time in total

----------

## wynn

```
VFS: Cannot open root device "sda3", Please append a correct "root=" boot option

Kernel panic: VFS: Unable to mount root fs on sda3" 
```

 Have you got a SATA drive? If so you will need to configure the kernel to include it â http://gentoo-wiki.com/HARDWARE_SATA says it better than I can.

----------

## Hadriel

put sata support (was module, now built in) into the kernel, still the same error.

----------

## wynn

Sorry.

I had a paused project to get Xen working. I've restarted it, gone through the gentoo-wiki instructions  and get the same error as you have.   :Sad: 

----------

## Hadriel

Thats good (or bad?) to hear. I just saw that I had this deprecated sata driver in my xen kernel and removed it. Still no luck. I have support for ReiserFS as well as sata and scsi support in the kernel, so xen SHOULD boot.

----------

## wynn

Perhaps you could try piggybacking a thread where people are discussing Xen who obviously have it running? Try a QuickSearch on "xensources".

This one has a kernel panic like us and has solved it:

```
http://forums.gentoo.org/viewtopic-t-468602-highlight-xensources.html
```

You could ask for his .config, /boot listing and the entry in grub.conf used to boot.

Best of luck.

----------

## xming

You need to make sure that SCSI, your SATA driver and your filesystem are compiled the kernel instead of modules.

----------

## Hadriel

ok:

scsi is built in.

sata is built in (as well as the intel driver for sata).

reiserfs (the only used filesystem on this machine) is built in.

anything missing?

----------

## kraut

maybe you are using old SATA drivers? try hde3 instead of sda3, does that work?

----------

## xming

add noreboot after your your boot option in grub, then xen won't auto reboot on error, than you can scroll back to see if the sata driver is loaded and detected all you partitions

----------

## Hadriel

@kraut

i know there is this deprecated sata driver, but i disabled it to enable the sata driver found under scsi low level driver.

something different bothering me: usb takes ages to get recognized, but  that has time until i get xen to boot at all  :Wink: 

ok, xen detects my hdd, strange thing is that it detects 2 hdds although there is only 1! there are ata1 and ata2, which he correctly calls "sata max udma/133 blabla".

----------

## wynn

 *Quote:*   

> strange thing is that it detects 2 hdds although there is only 1! there are ata1 and ata2

  It is detecting the interfaces, it is only later on that it looks to see if the i/f has anything plugged in. It's where it starts saying "Vendor" and talking about sda.

----------

## Hadriel

got it working. just did an emerge --sync and took xen-sources-2.6.16.26  :Wink: 

----------

