Backup Confusion - Win 10 VM Growing too Big

I'm sure this information is somewhere, but I have read everything I can find and still find myself confused about Parallels backups etc. I migrated from a Windows environment to Mac several months ago but need to run some legacy Windows software for now (accounting mainly). So I'm hoping someone can help me understand what is going on in my system. I am running Parallels Desktop Pro version 16.1.0 (48950) with Win 10 as a VM (not bootcamp).

My Win10 size is currently about 88Gbytes (it has a Windows.old folder and 20Gbytes of 1Note internal backups hence the size). All my documents etc are on the Mac not the VM. My current .pvm file is 210Gbytes! I have Smartguard turned on and optimized for Timemachine. This results in 3 snapshots.

I thought Snapshots were only storing the original plus "Snapshots" of changes, but it seems like it's keeping 3 full copies (although how you can know evades me). This does not seem to be what the documentation suggests, but...Is this config meant to keep 3 full images within the VM?

I'm not sure this size problem occurred with Version 15, so is it somehow related to "automatic disk space recovery" not working correctly?

How can I reduce the size of the .pvm file? Would I be better to isolate the .pvm file from Timemachine, disable all Parallels backups and simply taking copies of the PVM periodically?

I hope this all makes sense, I just seem to be missing something in my understanding of how this all works, but I cannot afford to have 1/2 my disk taken up by the Parallels VM.

thanks,
Allan

 

A bit further information.

I've now understood that I can open the .pvm and see it's contents in Finder. It's not the Snapshots that are taking the space its the Windows10.hdd file itself. It seems to grow each time I shut down the VM! But Windows Explorer says that the c:/ drive is only taking 88Gbytes so where is parallels thinking that space is taken?

 

Okay so I found: this link in the forums which explains the problem of Parallels not reducing volumes correctly when Windows has expanded and following the suggestions there have reduced my VM size, but somehow it has not returned the space to my Mac which is rapidly running out of space. I really need some help here. Clearly from the other thread, parallels is not managing the freeing up of space correctly. How do I get this space back to my Mac

 

I'm having a nice conversation with myself here . Gradually I'm solving things. Finder found the extra space after a reboot (probably could have got away with a Forced Relaunch but hey). BUT, now I want to fix the size of the windows VM to stop this happening again, but Parallels will not let me. It tells me that there is insufficient space on the Mac. The VM is taking up 89Gb and Finder says I have 340Gb available (as does Disk Manager). So what is going on with Parallels and what do I need to do? I really could do with some help on that bit. When I click on the "Expanding Disk" to turn it off, and click apply, it tells me I don't have sufficient room on my Mac!

 

if you haven't definitely do a "disk cleanup" on your windows c: drive. it's probably got all of the old downloaded updates, etc. i also turn off system protection for the drive since windows keeps rollback points. when i do that it keeps my windows vm to ~40-50 gb consistently.

 

Thanks Tony for your reply. I have run "disk cleanup" and removed the Windows.old folder (Windows forced me to go to 2004 last week). I have the roll back feature set to a 1Gb limit. I can live with that for now. I was able to fix the VM size to 128K eventually. Seems that Parallels does not pick up that the space has been returned to the Mac so was telling me I didn't have enough room. Rebooting solved that.

I'm still not happy with my understanding about how Parallels 16 seems to be handling reclaiming space. The automatic reclaim space option leaves you no way to know that its not able to do that because of some Windows hold of the space, you just see your MacOs space disappearing. And, I'm still a bit confused about how this is working and what the limitations are. Everything was working fine under Parallels 15 and Win10 1909. Anyway I've decided to invest in a 500Gb USB-C SSD and move the VM to there. Windows can take the whole drive if it wants without taking all of my Mac disk. And I'm happy to make manual copies of the VM for backup. It's not like it's going to have any data on it once I finish cleaning up some transitional stuff.