Open Ports

Check from the esxi host towards any given IP if a certain IP is reachable (when telnet is not available):

nc -w 1 -z <ip> <port>

SSH warning

After enabling the SSH login on the hosts, a warning shows up in the console. It can be disabled with

vim-cmd hostsvc/advopt/update UserVars.SuppressShellWarning long 1


In order to boot a Centos5.5 on an ESXi machine you need to alter the hardware a bit. Change the NIC and Hardware controller:

  • NIC: E1000
  • HDDControler: LSI Logic SAS


Scan SCSI Bus

When you add a new harddisk to your machine you do not necessarily want to restart the whole machine just to be able to access the new device. Instead, you can just simply scan for the new device and add it to your configuration.

A rescan can be issued by typing the following command:

echo "- - -" > /sys/class/scsi_host/host#/scan
fdisk -l
tail -f /var/log/message

Replace host# with the actual value such as host0. Find the scsi_host value using the following command:

ls /sys/class/scsi_host

More commands regarding adding and deleting devices you'll find here.

VmWare Converter

Converting physical machines or virtual machines into virtual machines (e.g. on vSphere, Workstation,etc).


kernel major revision as ERROR


During the conversion (roughly at 98% already finished) an error message appears during the re-configuration of the system by the converter engine.

Error message:

FAILED: An error occurred during the conversion: ' * got kernel major revision as ERROR:
kernel version has to be in format 2.6.*, version 2.6.32-358.6.1.el6.x86_64 is not supported (return code 1)'


You are using the newest version, aren't you? This has once been solved by going one step backwards from version v.5.1. to v.5.0.1. The conversion than finished successfully.

FAILED: Unable to obtain the IP address


The conversion process doesn't really start. Already in the beginning at roughly 1% the process times out trying to connect to the helper machine setup to receive the temporay copy of the system.

Error message:

FAILED: Unable to obtain the IP address of the helper virtual machine


The problem ist, that the VmWare converter Server can't reach the Helper system it creates. Within the options of the Conversion Wizard you probably need to assign an IP address to that machine and make it reachable. This usually happens when there's not DHCP available in the network.