Hidden files taking up disk space

Question

My son has been using my wife's computer and has instaled several apps including a screen capture prgram called debut. Now the computer gives a message that it is out of disk space. I set the view options to "calculate all sizes". When I look at the contenst of the user folder, they do not add up to what the finder says is there. The finder says there 92 gigs used, but the contents as show only add up to about 45 gigs. So I'm guessing that one of these apps has installed some sort of "hidden" files. Searching around the community here, I saw it was suggested to use OmniDiskSweeper. When I run that it shows that my "Library" folder inside my wife's "User" folder is about 50 gigs. However, that "Library" folder is not visible in the Finder view. Does anyone know why that would be? Also, having used DiskSweeper to reveal all the files, how do I know what is safe to delete from that "Library" folder?

Answer 1

This is what I do....I open terminal and issue the following commands (you need to be an administrator)..it will take a few minutes to run since it's counting up space
cd /
sudo du -d 1 -x -c -g
This gives a listing in GB at your root level
It should look something like this
MacPro:/ xxxxx$ sudo du -d 1 -x -c -g
Password:
1          ./.DocumentRevisions-V100
1          ./.fseventsd
2          ./.Spotlight-V100
0          ./.TemporaryItems
0          ./.Trashes
0          ./.vol
31          ./Applications
1          ./bin
0          ./cores
1          ./dev
1          ./home
5          ./Library
1          ./net
0          ./Network
0          ./opt
1          ./private
1          ./sbin
4          ./System
44          ./Users
1          ./usr
1          ./Volumes
85          .
85          total
I'm using 31GB in applications and 44GB in users.  That's the majority.  If you see big numbers in ./Volumes for example, that is the sign of a failed TM restore, etc...
Now I cd into Users (cd Users) and rerun the same command
MacPro:Users xxxxx$ sudo du -d 1 -x -c -g
1          ./bootadmin
44          ./xxxxx
1          ./Shared
44          .
44          total
You can see that I'm using all the 44GB, not the user bootadmin, not shared
Now if I cd into xxxxx and rerun the command I get this
MacPro:~ xxxxx$ sudo du -d 1 -x -c -g
1          ./.cups
1          ./.dropbox
1          ./.dvdcss
0          ./.idm
1          ./.ssh
0          ./.Trash
1          ./Applications
1          ./Desktop
10          ./Documents
1          ./Downloads
1          ./Dropbox
21          ./Library
1          ./Movies
1          ./Music
12          ./Pictures
1          ./Public
0          ./Sites
44          .
44          total
So I have 10GB of documents, 21GB in my Library, 12GB of photos
One more time in Library (cd ~/Library)
(truncated for brevity)
I have 7GB of application support and 12GB of mail
So with simple commands I can trackdown strageness with storage.  You can't know what to delete but you can ask here "why is this folder using so much space?"  Your son may have his own account and is using 40GB of space now.  My own son has downloaded several games on his mac where each one is 15GB.