LAMP How To – Open Source At Work

to turn off selinux during boot, append “selinux=0″ in the kernel parameters.

everything in emergency is readonly,
to fix things, we need to remount it as rw. errors in /etc/fstab is deadly.

mount -no remount,rw /

This is as simple as installing kmod-xen in the pv guest.
I could boot from rescue disk, then do a yum install.

If your guest is running

xm block-attach server_name /dev/cdrom r

to add cdrom in the config file

disk = [ "phy:/dev/vg/hermes,xvda,w", "phy:/dev/cdrom,xvdb:/dev/cdrom,r" ]

I was searching in the web and found some good postfix resource.
http://www.akadia.com/services/postfix_uce.html
http://www.cyberciti.biz/tips/postfix-spam-filtering-with-blacklists-howto.html
I thought they are clear and to the point. thumbs up for the authors.