How are virtual guests different from physical machines?

Virtual guests work like physical hosts, with some important differences.

Creating a new virtual guest

The process of creating a new virtual guest is very similar to the process of creating a new physical host, with the following differences:

Disk size

While disk space is allocated to virtual guests at the time of virtual guest creation, it is not actually occupied on the host until it is needed by the guest. At the same time, TeamForge Lab Management does not keep an up-to-date count of exactly how much disk space is in use on the virtual host.

In practice, this means:

Modifying hardware parameters of existing virtual guests

Some virtual guest hardware parameters can be modified after the virtual guest has been created.

Changing disk size
While changing the size of the disk is supported in TeamForge Lab Management, the change will not be reflected until you re-image your guest. And, in certain cases, it is possible for a change in the disk size of your guest to cause the guest to become unreachable, especially if you reduce the disk size. Therefore, we recommend that you change disk size on virtual guest only if you are going to immediately rebuild the guest.
Changing RAM size
Changing RAM size is a very low-risk operation. In order for the change to take effect, the virtual guest must be rebooted after the change is made in TeamForge Lab Management. Reducing the RAM available to your virtual guest can make the system run much slower.
Note: In between changing RAM size of the virtual guest and rebooting the virtual guest, you must wait approximately 5 minutes to insure your change is propagated.
Changing the number of CPUs
Virtual guests can support either one or two processors. Two CPUs for virtual guests are supported only if the virtual host has at least two CPUs. Like changing a virtual guest's RAM allocation, changing the number of CPUs in a virtual guest is a low-risk operation, and the virtual guest must be rebooted after the change has been made in TeamForge Lab Management.
Note: In between changing number of CPU's for the virtual guest and rebooting the virtual guest, you must wait approximately 5 minutes to insure your change is propagated.