I've been trying to get kernel 2.6.5 to work, but cannot get past the

> Kernel Panic: VFS: unable to mount root fs on unknown block (33,4)

issue. The problem has come up often on this forum and elsewhere. It is even addressed on the Slackware site (although their suggestion to modify LINUX.BAT wasn't acted upon since I could find no such file). I've tried every suggestion I've run across and cannot get past the panic. Is there a recent kernel that didn't have this problem? 2.4.22 worked fine, although I had not compiled it myself.

That usually means that you didn't compile support for your root file system in the kernel.

I could imagine the following reasons:

• as MS3FGX said, the root-filesystem is not compiled in the kernel nor present in initrd (easy to fix)
• you may need to boot with the option APIC enabled (but that was on kernel 2.4, SuSE 9.0 and Dell GX270)
• you are running a SATA-drive, which is on /dev/sdx instead of /dev/hdx
• you experience the same strange problem that I had with SuSE 9.0 on a Dell GX270. I fixed it, don't ask how, but I can send you my config-file for the Vanilla source on request.
• for the SuSE, an update-kernel is available that shifts you to the SuSE 9.1 kernel (did not work in my case)

In the boot messages, do you get something like this ?
This would show you if the harddrive gets recognized somehow. If not, I guess you need to play around with the drivers in the kernel config.

Good luck!

I should have said that I'm compiling the kernel in slackware and have removed Suse from my system.

<as MS3FGX said, the root-filesystem is not compiled in the kernel nor present in initrd (easy to fix)

Concerning compiling support for the root file structure in the kernel, I have enabled Reiserfs support during "make Menuconfig". I searched the rest of Menuconfig trying to find anything on boot, etc., and found nothing. I just tried to look at initrd, /dev/initrd, but when I "view" it, I get "initrd is not a file", and when I cd initrd, I get "initrd is not a directory", so WTF is it?

<you are running a SATA-drive, which is on /dev/sdx instead of /dev/hdx

No SATA-drive, and if I recall correctly, the hard drive was detected. If I can see dmesg for a failed boot, I don't know about it.

initrd is a compressed (?) ramdisk (a file!) that can be found in /boot (at least in SuSE, sorry but I don't know much about slackware). It is made (in SuSE) by calling the command 'mkinitrd -k <kernel-image> -i <initrd-name> -m <modules to load(like reiserfs)> -d <root-device(eg. /dev/hda1)>' (more options see 'man mkinitrd'). But if reiserfs is compiled into the kernel (CONFIG_REISERFS_FS=y instead of m) this is not needed.

Maybe it is an issue of your bootloader. Did you pass the correct option like root=/dev/hdx or root(hd0,0), depending on the location of your root-device, to the loader? The 'LINUX.BAT' thing sounds like you are loading linux from a running windows? I guess it would need some more info on that.

I am sorry that I can't help more...

I did a google search on the problem and came up with a link to the slackware site, which had a FAQ dealing with kernel panic. I didn't look close enough to notice that the question was under ZIPslack, so LINUX.BAT does not pertain to my setup.

> Did you pass the correct option like root=/dev/hdx

yes. I double checked that.

I'll have to wait to get home to check my initrd settings using mkinitrd. thanks for the responses.

Well first off, does your system even use an initrd?

And second, you say your root partition is ReiserFS, and you added support to your kernel, but did you enable it as compiled into the kernel, or as a module?

I compiled Reiserfs into the kernel, not as a module.

Concerning whether my system uses initrd, I have /dev/initrd. I only assumed that since it is there, it is used. I don't know that much detail about how linux works to know for certain. However, I just tried to pull up a man page on mkinitrd and I was notified that there was no entry for it.