VMWare Server

Obtaining accurate server time is really causing me difficulties

Question: I have a problem with CentOS Time setting. I have Enable Network Time Protocol enabled and have 2 servers listed. The server will not update itself. I have to go into Date & Time setting, click the Network Time Protocol tab and then click OK for it to update. Any ideas?
Answer: The GUI is not well suited to solving this issue speedily.
- As root in a console:
```
/sbin/service ntpd stop ; /usr/sbin/ntpdate -s tick.usno.navy.mil &&
/sbin/hwclock -w ; /sbin/service ntpd start
  
```
- If that does not work, you have issues out of scope of the local time management application.

If you are on virtual hardware, other issues exist and are documented elsewhere. VMWare is what is being referred to -- For more info see:

http://www.vmware.com/info?id=97 (Windows)
http://kb.vmware.com/kb/1591 (Linux)
http://kb.vmware.com/kb/1420 (Linux)

One of the known problems has to do with the timer frequency set in the kernel. 2.6 kernels request clock interrupts at 1000Hz and it can be difficult for the virtual machine to keep up (see this bug report for details). To remedy this, CentOS offers kernels with the clock rate set to 100Hz. They are named kernel-vm and are located in the testing repository. Refer to CentOS Repositories to set up this repository. You can install the kernel-vm package by:

yum --enablerepo=c5-testing install kernel-vm

(Substitute the c4 for c5 to install the CentOS-4 version)

CentOS also offers (under testing) vmware-images, prebuilt and updated. See here for details.

Change guest VM networking bridge to work across host wireless connection

You can easily change eth0 to a different location so that you don't have to use NAT across your wireless connection. First stop the service vmware, but first make sure all guest VMs are not running.

# service vmware stop

Next, edit the vmware configuration file and change all instances of eth0 to your wireless connection. In my case, this is eth1.

# vim /etc/vmware/locations 
answer VNET_0_INTERFACE eth1
answer VNET_0_INTERFACE eth1

Save and exit this file. Now start vmware services back up.

# service vmware start

You should now be able to bridge across your host wireless and VM with no more fuss. You also don't need to worry about loading any wireless drivers on the guest OS, because it's bridged across the virtual VMware network interface.