Thought this post might be useful to other noobs if some experienced folks could confirm the information.
I was trying to boot to single user mode (ahead of *needing to*). In researching this I saw several posts with grub.conf files like this:
kernel /vmlinuz-x.x.x.x ro root=LABEL=/1
but my CentOS 5.3 'default' (i.e., untouched by noob hands) grub.conf looks like this:
title CentOS (2.6.18-128.el5xen)
module /vmlinuz-2.6.18-128.el5xen ro root=/dev/VolGroup00/LogVol00 rhgbquiet
- the difference being that the 'kernel' line is now the xen image and the OS I want in single-user mode is on the "module /vmlinuz-2.6....." line. Many of the posts I saw suggest adding '1' or 'single' to the "kernel" line (via the grub boot time interface for a one time execution). What I did was add '1' to the "module /vmlinuz-2.6....." line and it worked.
I hope someone finds this useful.