Virt Block

Lately an updated patch set has been posted to list, which is splitted and improved according to Kevin’s instructions, The patches included monolithicFlat and monolithicSparse support.

I have downloaded roughly a dozen of vmware appliances, they have various formats like monolithicSparse, twoGbMaxExtentSparse, vmfs and raw. Flat formats are hardly used for VM publish and transfering, and also is ESX Server Sparse Extent. I have to turn to ESX and figure out how to use it to produce the latter.

As we seem only a step away from twoGbMaxExtent{Sparse/Flat} support, I decided to take them prioritized and it turns out that under the structure of VmdkExtent array, it’s not much work to get it out. By now I have just implemented the two formats and we have supported four types in all:

• monolithicFlat
• monolithicSparse
• twoGbMaxExtentFlat
• twoGbMaxExtentSparse

Testing with downloaded appliance (such as Ubuntu, Fedora and Mint virtual machines), it shows that the format works well.

The cluster compression support and Stream Optimized Compressed Sparse Extents is delayed because I want to have some real world sample image ahead, to prop up the development. I’ll continue to find in vmware appliance directory and try more vmware applications to create ones.