PXE boot unable to mount device ram0

I am trying to set up PXE booting for a bunch of diskless clients using SuSE 11.3. The PXE part is fine - DHCP is functioning properly and the client retrieves the kernel and initrd just fine. It starts booting and eventually dies with this error:

VFS: Cannot open root device “/dev/ram0” or unknown block(0,0).
Please append a correct “root=” boot option; here are the available partitions: <none listed>

Here is the relevant supporting info:

initrd: created from a super-basic install of SuSE 11.3 onto an almost identical machine. fstab and some other files were then edited for the image.
hardware: This is a Dell “DCS23” which is basically a stripped down Poweredge 1950 III

cat etc/fstab

/proc                /proc                proc       defaults
/dev/ram0            /                    ext2       defaults

ls -al dev/ram*

brw-rw---- 1 root disk 1,  0 Jan 26 15:21 dev/ram0
brw-rw---- 1 root disk 1,  1 Jan 26 15:21 dev/ram1


prompt 1
default linux
timeout 1

label linux
    kernel vmlinuz
    append initrd=/rootfs.gz ramdisk_size=1000000 root=/dev/ram0

Additional info
None of these machines by default come with the /dev/ram* nodes - I had to create them. I am not sure if that’s the problem or not though but it seems weird that they aren’t created by default.

I can’t find anything else on the web and I can’t really think of any other ideas on how to solve this. Can anyone suggest anything for me to try?

Can’t help with PXE but you do know that 11.3 is at the end of it’s support life??