IT reseller takeaway: Before you attempt a VMware configuration, make sure VMware ESX Server is ready to communicate on your clients' networks. This book excerpt from Virtualization: From the Desktop to the Enterprise offers best practices for verifying and viewing ESX Server files.
When ESX Server is booting, you can get a good idea of what services are being loaded. If
you've used Linux-type operating systems, you'll encounter a familiar boot process. Before
you start the configuration of ESX Server, let's make sure the system is ready to communicate
on the network. For Unix and Linux users, this section will seem basic, but it's essential for
Microsoft administrators. If you're familiar with the information, skim this section and use it
as a review.
You'll want to check the server's basic configuration, so you'll need to gain shell access by
pressing Ctrl+Alt+F2. You can switch between shell sessions by pressing Ctrl+Alt+F1 through
F12. So you can get an idea of how it works, toggle between the Welcome screen and the shell
Login screen.
At the shell Login screen, enter the administrator's username root, and use the password
you configured earlier for the account.
Caution: Unlike Microsoft OSs that are generally case insensitive, every command in Linux-like operating systems is CaSe sEnsiTive. Everything! For instance, ROOT isn't the same thing as Root or root. These
are all three different user accounts, and only one is the superuser administrator account—root.
After logging into the ESX Server CLI, the first thing you'll want to check is the system's
IP address information. Type ifconfig | less at the command line. (You could use the pipe
with the more command, but less allows scrolling up and down with the arrow keys. Type q to
quit.) You should have information for the loopback address (lo) and a minimum of two Ethernet
controllers (eth0 and eth1). Remember that you need at least two NICs to bridge or NAT
VMs to your network. If you dedicate a single NIC to VMs, you'll lose the ability to connect to
the Service Console with a Web browser.
Confirm that your server's information is correct, and then test the following using the
ping command. You can use Ctrl+C to break out of the looping echo requests and echo replies.
Test the server's TCP/IP stack by pinging the loopback address with ping 127.0.0.1.
Test the server's default gateway with ping .
Test DNS by pinging a Web site with ping www.apress.com, for example. Some Web
servers block ICMP traffic, so you may get only the domain name to resolve to an IP
address.
Viewing configuration files
If you have a problem with the ping tests listed previously, you'll have a problem configuring
ESX Server through a Web browser. If no IP address information exists, you can attempt to use
the setup command to configure your IP address information. A better solution to verifying
configuration information is to check the configuration files from the command line. Though
we could easily turn this into a Linux tutorial, we'll just walk you through the basics.
Editing configuration files starts with a good text editor and enough knowledge to be
dangerous, so now is as good a time as any to discuss the Vi editor: some of us hate it, and some
of us love it. It comes with nearly every version of Linux; you can even find it in the Microsoft
NT Resource Kit. Whether you're a fan of Vi or not, it's an excellent text editor that gets the job
done. Table 5-3 lists the commands you'll need to memorize for ESX Server administration.
Table 5-3. Vi Survival Commands
Command
Action
vi
Starts the Vi editor
vi <filename>
Starts Vi and opens the given file for editing
:q!
Exits the Vi editor without saving changes (quit!)
:wq!
Exits the Vi editor and saves changes (write and quit!)
:set nu
Turns on line numbering
esc
Exits text insert mode
i
Enters text insert mode
Arrow keys
Navigates the cursor
Backspace key
Deletes previous character
Delete
Deletes selected character
Vi has two different running modes: command mode and edit mode. In command mode,
every keystroke is interpreted as a command and performs file functions such as editing and
saving. These commands are referred to as colon commands because they start with a colon.
You know you're in command mode because you won't see "INSERT" in the lower-left corner
of your display. The lower-left corner should display a colon when executing colon commands.
If you have any doubts as to what mode you're in, press the Escape key (several times) to enter
command mode.
In text mode, typed characters are echoed to the screen and temporarily become part of
the open document. Enter text mode from command mode by typing a lowercase i (for insert
mode). Use the arrow keys to navigate the cursor, and use the Backspace and Delete keys to
remove characters. To quit without saving your current work, or to save your current work and
quit, refer to Table 5-3.
Now that Text Editing 101 is out of the way, you can verify your ESX Server configuration
information using the filenames listed next. For each file, open and view your system's information.
If anything is incorrect, take a moment to fix any errors and save your changes.
You can find configuration files relating to the host name (FQDN) of your system in three
places:
vi /etc/sysconfig/network
vi /etc/hosts
vi /usr/lib/vmware-mui/apache/conf/httpd.conf
IP address configuration information for the first network adapter is located in
/etc/sysconfig/network-scripts/ifcfg-eth0.
The contents of the ifcfg-eth0 file will look similar to the following:
IP address information for the second network adapter is located in /etc/sysconfig/
network-scripts/ifcfg-eth1.
The contents of the ifcfg-eth1 file will look similar to the following:
DEVICE=eth1
ONBOOT=yes
You can find DNS server configuration information in the resolv.conf file. Review the
contents of it by executing the following command:
vi /etc/resolv.conf
Default gateway information is located in the network file. Make sure the default gateway
is properly set. If not, you'll spend needless time troubleshooting your host. Verify your host's
settings with the following:
vi /etc/sysconfig/network
After verifying and making any necessary changes, restart the networking service by
entering the following command:
service network restart
Continuing at the CLI, execute hostname (for example, hostname www.apress.com)
to make the host name change effective without a reboot.
Next, repeat the ping tests, and verify your system's host name with uname –a.
With positive results from network connectivity and name resolution testing, the ESX
Server installation is complete. You can move onto your post-installation housekeeping. You'll
perform these tasks by configuring and using the MUI.
Chris Wolf is an instructor at ECPI Technical College, as well as a leading industry consultant in enterprise storage, virtualization solutions, and network infrastructure management. He has a master's degree in information technology from Rochester Institute of Technology, and his IT certification list includes MCSE, MCT, and CCNA. Wolf authored MCSE Supporting and Maintaining NT Server 4.0 Exam Cram, Windows 2000 Enterprise Storage Solutions and Troubleshooting Microsoft Technologies, and he contributes frequently to Redmond Magazine and Windows IT Pro Magazine. Wolf also speaks at computer conferences across the nation.
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