OK, I'm trying to run Mandrake 10 on a spare machine as a web server, and just something to learn on. I'm fairly well versed in IT in general, but I've never quite caught on to the linux bandwagon. Anyhow, here's some background to my question: I installed Mandrake and had everything up and running for a while, but found I needed to borrow the CD-RW drive for another machine. That's when I first got this error:

VFS: Mounted root (ext2 filesystem)
Red Hat nash version 3.5.18-mdk starting
Loading jbd.ko module
Loading ext3.ko module
Mounting /proc filesystem
Creating device files
VFS: Cannot open root device "341" or unknown-block(3,65)
Please append a correct "root=" boot option
Kernel Panic: VFS: Unable to mount root fs on unknown-block(3,65)

Removing this drive prevented my machine from booting. So I reinstalled the drive, and everything was working OK.

Later, I did some case upgrades that swapped the order of the CD-RW and the HDD on the cable (i'm using cable select). I got the same error as above! Eventually I determined that this was the problem, swapped the order of the drives on the cable, and everything came up properly again.

Anyhow, here is my question. When I look at those error messages above, I don't understand what any of that means. How should I have gone about diagnosing a problem like this? Where can I learn more about VFS and how it configures devices in the system?

If you remove a drive or change the order the names of the remaing drives change,. If the kernel is expecting eg hdc would become hdb if a drive was removed. If the kernel is expecting hdb to have ext3 and it has reiserfs instead, you'll get the VFS error.

I don't know how your system is set up, but any physical changes you make should be reflected in your /etc/fstab file