VM Fusion 8.X keeps growing a lot and keep needing to reclaim space

[mrweemote]

This is the first I have encountered this strange issue.

Client is running VMWare 8.X on MacOS High Sierra.

Normally, the VM size is around 45G. This iMac 2011 model has a 256G SSD installed. The VM is running Windows 10 and they only use it to access the UPS Worldship application.

Anyway, it seems after several weeks, the VM grows out of control and eventually reaches about 200G. Each time when this happens I reclaim the space and it goes back down to 40G. In windows, the C: drive is only showing about 1% of fragmentation.

Any ideas of why this is occurring in a cycle?

[scott28tt]

What size is the virtual disk?

Regardless of fragmentation, if Windows is writing to the blocks of the virtual disk Fusion has to write to the corresponding blocks of the virtual disk file...

[Technogeezer]

In the same vein as @scott28tt , 

• how much of that VM’s disk is being reported as used by Windows? It sounds to me that if you are getting so much space back on a Fusion reclaim that your virtual disk may be over sized. If Windows is not using much of the virtual disk, consider taking steps so that the Virtual disk size is lower than you have today. 
• how much memory is allocated to that VM? Could it be starved for memory and therefore is requiring Windows to allocate paging files on the virtual disk?
• Are you running Defrag utilities from within the VM? If so, stop it. You are not gaining anything speed wise and are causing excessive wear on your SSD.