More on disappearing disk space

Last week we reported that in some instances, Mac OS X volumes will display a significantly lower remaining disk capacity than expected based on installed applications and residing files. Sometimes the dramatic loss of space can happen suddenly - after a Mac OS X update or application installation - or gradually over time.

We've now identified some additional culprits behind large, extraneous file creation:

Photoshop scratch files Steve Talley writes "I actually just had this happen on a user?s machine.  He had a 40GB main partition, which should have had at least 20GB of free space left.  Suddenly, an error message popped up stating that he had 0 megabytes of space available. 

 "In this case, Photoshop had not cleaned up its temporary, invisible scratch files.  Photoshop was set to use the 40GB startup partition as its first scratch disk. It left behind two very files, one of which was 16GB, and the other was 5GB.

 "I found them by doing a Find in the Finder, selecting Specific Places, and placing a check next to his main partition.

 "In the lower portion of the window where you can add search criteria. I selected Visibility, and then Invisible items.  I also clicked the plus icon to add another search field, and specified that the items found must be larger than 5000K. 

"This resulted in very few search results, making it easy to single out the files that should not be there.  The scratch files had the same name as the Photoshop files he had been working with."

  CUPS printing temp files Guillaume Gete found that the CUPS printing server, which creates an incredible amount of temp files in /var/spool/cups/tmp/, was unexpectedly filling up his primary volume.

To delete the files, Gete used the following Terminal command:

• sudo rm -rf /var/spool/cups/tmp/*

Clean-up application suggestions Several readers have suggested utilities that can identify potentially useless files, as well as monitor disk space statistics:

MacFixIt reader Michael writes "I have found that an easy way to identify the culprit when a rogue file or files is unnecessarily taking up a large amount of space is to use Disk Inventory X. This gives a graphical representation of the file system, allowing you to quickly spot individual files or groups of files. This can be done either beneath a chosen folder (such as ~), or over the whole file system."

OmniDiskSweeper allows users to see the size of folders in columns view, including invisible files and folders, so it is very easy to check for where new files are accumulating.

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