> 2. It's just hang. Not reboot. I have to power off the VM and power on. > The ESXi host has many VM in it and only my that VM has problem. If you can't trace your problem to anything else, then I would look at the ESXI configuration for that VM. If there are other CentOS/Redhat 5 VM's on the ESXI server, check the vmware configuration to see that they are the same. In particular, make sure the OS is set to the correct thing for Redhat 5. VMware, in its hardware emulation, makes assumptions about clocking and possibly other kernel options and if the VM config does not agree with the running kernel, you can have problems. Nataraj