6.0.3

Table Of Contents
Securing Virtual Machines 7
The guest operating system that runs in the virtual machine is subject to the same security risks as a physical
system. Secure virtual machines as you would secure physical machines.
This chapter includes the following topics:
n
“Limit Informational Messages from Virtual Machines to VMX Files,” on page 217
n
“Prevent Virtual Disk Shrinking,” on page 218
n
“Virtual Machine Security Best Practices,” on page 218
Limit Informational Messages from Virtual Machines to VMX Files
Limit informational messages from the virtual machine to the VMX le to avoid lling the datastore and
causing a Denial of Service (DoS). A Denial of Service can occur when you do not control the size of a virtual
machine's VMX le and the amount of information exceeds the datastore's capacity.
The conguration le containing the informational name-value pairs is limited to 1MB by default. This
capacity is sucient in most cases, but you can change this value if necessary. For example, you might
increase the limit if large amounts of custom information are being stored in the conguration le.
N Consider carefully how much information you require. If the amount of information exceeds the
datastore's capacity, a Denial of Service might result.
The default limit of 1MB is applied even when the tools.setInfo.sizeLimit parameter is not listed in the
advanced options.
Procedure
1 Find the virtual machine in the vSphere Web Client inventory.
a Select a data center, folder, cluster, resource pool, or host.
b Click the Related Objects tab and click Virtual Machines.
2 Right-click the virtual machine and click Edit .
3 Select VM Options.
4 Click Advanced and click Edit .
5 Add or edit the tools.setInfo.sizeLimit parameter.
VMware, Inc.
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