Hi Andre (or should I address you as a.p.?) - I actually have done a very similar removal of a .vmdk file from the datastore like Troy and was following your thread conversation with Troy.
I started down this path, because after I built a GNS3 environment to simulate/practice on building networks, one of the
appliances used all the disk space (or ran out of swap space), so I thought to delete some large files (older - thinking
those files are no longer used) - that was a mistake 
So, I saw this thread in the vmware community and wanted to pursue. I noticed that you have helped modified the WebServer0.vmdk file (in Troy's situation) ....
this is where I got lost! Would you be able help guide me in your thought process so I can create a new .vmdk file for this purpose, or is it
different enough that the method may not work? I'm willing to give it a try and open for suggestions.
In Troy's VM (the Web you have made (or at least I think you have made):
1. I noticed the following changes:
CID FROM: "1065ec08" TO: "e056a0a1"
parentCID FROM "ffffffff" TO "1065ec08"
createType FROM: "vmfs" TO: "vmfsSparse"
2. You added:
parentFileNameHint "WebServer0.vmdk"
3. Under Extent description:
FROM: "RW 419430400 VMFS "WebServer0-flat.vmdk"
TO: "419430400 VMFSSPARSE "WebServer0-000001-delta.vmdk"
4. Removed everything below the two comments:
# The Disk Data Base
#DDB
How did you determine the new values? Or rather, how would I determine the correct modifications based on my VM files (i.e. GNS3-2.1.15.vmx)?
This is what I have:
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A single DataStore [Identification = "datastore1 (2)"] with 27GB free space.
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************* Begin ***********************
output from the 'ls -elisa > filelist.txt:
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total 125181968
264241540 8 drwxr-xr-x 1 root root 2380 Mon Jun 10 17:44:18 2019 .
4 1024 drwxr-xr-t 1 root root 1960 Fri Mar 29 20:06:30 2019 ..
549454212 1213440 -rw------- 1 root root 1241559040 Mon Jun 10 05:45:30 2019 GNS3-2.1.15-000001-delta.vmdk
553648516 0 -rw------- 1 root root 325 Mon Jun 10 05:45:09 2019 GNS3-2.1.15-000001.vmdk
545259908 1024 -rw------- 1 root root 27997 Wed Apr 3 01:45:37 2019 GNS3-2.1.15-Snapshot1.vmsn
322961796 1024 -rw------- 1 root root 8684 Mon Jun 10 05:45:30 2019 GNS3-2.1.15.nvram
276824452 0 -rw-r--r-- 1 root root 615 Wed Apr 3 01:45:40 2019 GNS3-2.1.15.vmsd
268435844 8 -rwxr-xr-x 1 root root 2577 Mon Jun 10 17:23:17 2019 GNS3-2.1.15.vmx
272630148 0 -rw-r--r-- 1 root root 266 Fri Mar 29 20:06:32 2019 GNS3-2.1.15.vmxf
557842820 21562368 -rw------- 1 root root 22079021056 Mon Jun 10 05:45:30 2019 GNS3-2.1.15_1-000001-delta.vmdk
562037124 0 -rw------- 1 root root 330 Mon Jun 10 05:45:20 2019 GNS3-2.1.15_1-000001.vmdk
289407364 102400000 -rw------- 1 root root 104857600000 Wed Apr 3 01:42:10 2019 GNS3-2.1.15_1-flat.vmdk
293601668 0 -rw------- 1 root root 508 Wed Apr 3 01:21:31 2019 GNS3-2.1.15_1.vmdk
515899780 0 -rw-r--r-- 1 root root 0 Mon Jun 10 17:44:18 2019 filelist.txt
478151044 1024 -rw-r--r-- 1 root root 42845 Mon Jun 10 05:55:16 2019 vmware-1.log
494928260 1024 -rw-r--r-- 1 root root 53217 Mon Jun 10 07:57:34 2019 vmware-2.log
511705476 1024 -rw-r--r-- 1 root root 52960 Mon Jun 10 17:23:18 2019 vmware.log
************* End **************************
************* Begin ***********************
zip file of all the "small" files from my VM (GNS3-2.1.15) including filelist.txt
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Given this information, would you have some spare cycles in your days to help me? If you don't think it is possible, I understand and am willing
to create this GNS3-VM environment from scratch - still a great learning experience. Or if you beleive it is possible, but don't have the time,
that is fine as well... I'll give it a go on my own and do a little more research. Thanks for you time. Ernie