@Anselm_von_Seherr-Th If you do not have enough space to even move the Insync folder once, please follow the following steps very carefully, if you have any questions/need clarification on any of the steps, then please ask/seek clarification first as mis-performing them may lead to trashing/loss of data on Google Drive web:
1) Quit Insync
2) Let's say your current Insync folder is the network path
N:\Insync-Folder, move ALL its children files & folders say, AFolder, BFolder, CFile.ext etc. to a new folder say,
3) Delete the empty folder
4) On Local drive, create a new folder say,
5) Create symlinks inside this newly created local folder to all the immediate children files & folders (AFolder, BFolder, CFile.ext etc.) of
N:\External-Location by running the following commands:
MKLINK /D "C:\Users\[Username]\Insync-Folder\AFolder" "N:\External-Location\AFolder"
MKLINK /D "C:\Users\[Username]\Insync-Folder\AFolder" "N:\External-Location\BFolder"
MKLINK "C:\Users\[Username]\Insync-Folder\CFile.ext" "N:\External-Location\CFile.ext" (Note the missing
/D parameter in case of files)
6) Ensure that the folder
C:\Users\[Username]\Insync-Folder has the exact structure/files as that of the erstwhile
7) Start Insync
8) Insync will complain that
Syncing is paused because the folder N:\Insync-Folder is missing
9) Go to account settings, click "Locate...", select the Insync folder
C:\Users\[Username]\Insync-Folder -> click "Apply Changes"
It is on the road-map to support "Add to Insync" even when the main Insync folder for the account is on a network drive on Windows. However, it is not a priority at the moment.