VMware Lab Manager, Databases, and Deltas

We are just开发者_如何学C starting to install WMWare Lab Manager and there is one thing I cannot figure out and that is databases and deltas.

Scenario. We create a base image of Database-1 which is then cloned for people to do testing on. We will call that database Clone-1. Now a developer comes along and decides he would like his own copy of Clone-1 so that his work does not interfere with the rest of the team. The developer creates a clone from Clone-1 which we will call Personnel-Clone-1. Now when the rest of team updates, inserts, and deletes records from Clone-1 does the developer see those changes in Personnel-Clone-1? If so it would appear that changes to Clone-1 could make the Personnel-Clone-1 unstable. On the other side of the coin if Personnel-Clone-1 is a complete copy of Clone-1 that would seem like it would eat up a lot of disk space.

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The user using the source of the clone will never see the changes made to the clone. Lab Manager creates linked clones of the virtual disks (VMDKs) when it makes a clone of a template or configuration. Linked clones similar to snapshots where a delta disk is created for the clone. The delta disk is small, initially only a few megabytes. Lab Manager will reference the source VMDK + the delta disk. Most blocks are read from the source disk. However when data starts to be written in the clone changing what it is in the source disk Lab Manager will do a copy-on-write and record the new data in the delta disk. The new data blocks will then be read from the delta disk instead of the of the source of the clone. Linked clones can be be made of these delta disks as well creating a long tree. If you look at your datastores in Lab Manager an view the context view, Lab Manager will show you a graphical view of the linked clone tree.