I've had to move a few large folders from my C: SSD to another drive. I've placed a couple of junctions on C:, pointing to the moved folders. Everything works fine.
But since junctions are at such a low level, the C: drive appears to be using the same amount of disk space as before, even though 20GB of files have been physically removed.
This raises an unsettling question -- how does one find out the actual space available on a drive with junctions?
Also, if junctions really are counted as local storage, then it seems impossible to have a junction to a folder that wouldn't already fit on the local drive. Which seems to mean that there's no point in using junctions the way I've done, because it's apparently not saving any space.
Worse yet, if I create a junction to an empty folder that easily fits, and then add contents to that folder, what happens when the remote folder contains more data than would fit?
I realize this isn't exactly a DOpus topic, but I'm not sure how to interpret the drive free/used numbers I'm seeing in DOpus (and also in Win Explorer). IAC, I'd love some clarification from the great minds who hang around here . . .
That is not how drive used/free space works in Windows. Junctions pointing to other drives do not use up space on the drive they are on; only the drive they point to.
But you may be looking at something which displays something else.
The free/used space for the drive shown in places This PC (aka My Computer aka Computer) show the space used on each drive and should not react thw way you've described.
The folder size column when in a normal folder, on the other hand, simply totals up the sizes of things below it, wherever they are.
Thanks, Leo. That's what I had thought, but in a massive reorganization involving junctions to DropBox stores, and a few across local disks, I thought I had calculated the free space on C: correctly. I just recalculated it, removed the junction, and (of course) it didn't change. So thanks for clarifying, and not calling me an idiot.
One further thought:
To confirm the total space on C:, I wanted to add up all the byte size values displayed in a DOpus lister. I thought I could capture the lister with all the displayed sizes, tab-delimited, and paste it into Excel. But the Edit...|Copy Other...|Complete Folder Listing output doesn't include the folder sizes.
(It also uses spaces to align columns, and I haven't (yet) found an option to use tabs instead. But I can easily trim the unwanted columns, so that's not a significant hassle.)
Is there some way to get a Complete Folder Listing that includes all the columns displayed in the lister? This would be handy in a lot of scenarios.
Tools > Print / Export Folder Listing lets you customize the output more, including options to calculate folder sizes and to output as a .csv file which will be more suitable for loading into Excel.
The folder sizes which it calculates will include the space used below junctions, and will not include the space used in some system folders which you cannot normally access (e.g. C:\System Volume Information).