Optimizing a disk dedicated to VMWare machines

[thedave]

I've been wandering the forums a bit, but haven't quite found what I'm looking for yet, so I thought I'd throw my idea in a post and hope that someone can take the time to tell me where I'm wrong?

I spend much of my life living in 4 virtual machines (VMWare workstation).  To that end, I've got a hard drive dedicated to these VMs, and I don't need to worry about interactions with any other files on the drive.

I've configured the VMDX files to use expanding files, with each file being limited to 2GB.  Since I use snapshots heavily, there is little performance to be gained by going to fixed sized VMDK files.

So the above being said, my thinking is that my optimum layout would be to sort files by directory, leaving approximately 5GB of free space after each directory.

The goal is twofold 1) This will help reduce seek times within a particular VM while it's active by grouping all files related to a given VM together.  2) While I can hope Windows will be smart enough to write related files into this space, even when it doesn't happen, I'm thinking future defragmentations will be faster due to this space being available.

Am I on the right track here?

I'm not really clear if SortByName sorts by the full path+filename, or just the filename, can someone clarify?

Am I reinventing the wheel for a script that has already been written?

[thedave]

Ignore my "SortByName" question, I decided to actually pay attention reading the helpfile.

[sag47]

I attempted something similar in a script that I wrote:
http://www.clubbleach.org/forums/showthread.php?p=4156699

But I'm not sure of the results (currently on day 2 of defragging and still going).  So I guess I can let you know when it's finished if it worked the way I wanted it to.

[jeroen]

I've configured the VMDX files to use expanding files, with each file being limited to 2GB.

From a defragmentation point of view it is better to use fixed size virtual disks, so they will not get fragmented and you can run MyDefrag less often.

leaving approximately 5GB of free space after each directory.

Feel free to do so, but sadly enough Windows will not (always) use that space when a virtual disk needs to grow.

p.s. It is also important to run MyDefrag inside the virtual machines, not only on the host.

[Kasuha]

My opinion is:

If a single VM image is used at a time most of the time, it's better to have it defragmented but its position on the disk is not that important. These files are huge and they will get to the 'slow zone' soon anyway. So simple defragment(fast) should do the trick most of the time and only when the free space becomes too fragmented to prevent this command to work it's time to pack them together by some of SortBy... commands or MoveDownFill(). FastFill() is probably not going to help here and FastFill(WithShuffling) is extremely ineffective on such configuration so I don't recommend it.

If multiple VM images are used at a time (e.g. on a VM server) ... then fragmentation of individual files is not that important because 'access fragmentation' caused by interleaved access to individual images is the main problem. Occasional SortBy... time to time to defragment them and pack together at the same time is a good idea, but for the rest I'd simply use ForcedFill() just to keep them in one block.