I installed CentOS 5.6 and was getting the following 2 warning messages at boot time:
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
WARNING calibrate_APIC_clock: the APIC timer calibration may be wrong.
To fix these, edit /etc/grub.conf and change this line as follows:
kernel /boot/vmlinuz-2.6.18-238.9.1.el5 ro root=LABEL=/ rhgb apiccalibrationdiff=10000 divider=10
So you have to add the following:
That should do it.
VMWare KB About APIC Warning Message
Article to Fix the KDump/KExec Warning at Boot Time