Section 3.5. Modify Your Master

3.5. Modify Your Master

Once you have a well-tested and trusted Gold Master, guard it well. As mentioned earlier in this chapter, it's a good idea to make a copy of it for safekeeping. You can use another copy of your Gold Master to test security patches, hotfixes, and service packs. Make sure you test any software package or configuration change on a copy of your Gold Master before applying the change to it. Of course, over time your Gold Master will have to change to keep up with operating system improvements as well as VMware virtual hardware improvements, but VMware allows for enormous flexibility when it comes to testing.

When making changes to your Gold Master, we recommend first putting the virtual disk in Undoable Mode. If you remember, this is the disk mode option that allows you to apply or discard changes when the virtual machine is powered down. If for some reason something goes wrong with your testing and you need to get back to the state your virtual machine was in prior to applying the software or configuration change, Undoable Mode allows you to revert to the state before the change. However, if the changes you make to your virtual machine are successful and you want to apply them, Undoable Mode allows for this as well. This snapshot-like functionality is a tremendous time-saver and provides excellent and flexible testing and restore possibilities.