Linux freeze at reboot

Problem:  My Linux environment (Oracle Linux 5 update 7 on Dell T1600) goes through the entire shutdown sequence normally, then hangs on a blank screen at the point when it would normally reboot the computer. It has to be manually power down and restart

Solution: Add "reboot=b" to kernel parameter (for Grub, it is inside /boot/grub/grub.conf)

For 64-bit OS, you may need "reboot=p,e,f"

Here is a excellent link about this topic

http://linux.koolsolutions.com/2009/08/04/howto-fix-linux-hangfreeze-during-reboots-and-restarts/

Update (July 3, 2012) : The following also fix the problem:

"VT for Direct I/O" from the bios

Install VMware Tools or Virtual Guest Addition for Oracle Linux

Problem: Get your Oracle Linux ready to install  VMware Tools or Virtual Guest Addition.

Solution: Oracle Linux by default uses Oracle's own unbreakable kernel, so if you install VMware Tools or Virtual Guest Addition, you need to get the correct header files to do the compilation. Here is the "yum" command to get all you need:

yum -y install kernel-uek-headers-`uname -r` gcc kernel-uek-devel