I have used disk utilities to copy and burn dvds (not copywritten) several times. Now when I try to create a new disk image file I get a window that says "Your startup disk is almost full. You need to make more space available on your startup disk by deleting files". I have deleted everything else that I had as an image file, plus pictures, ran MacJanitor and am still getting that window. What am I doing wrong? Thanks
thanks for responding so quickly..Finder says I have 1.3GB available on the HD. No, I'm not using FileVault, thanks for the info on OmniDiskSweeper, I'll try that out. My gut feeling is that the problem is not about space available, but that is what is referenced when it stops the imaging process.
Oh no, 1.3 GB is even dangerously low for OSX, it may decide it needs 10GB for VM space at any time, I have 6 GB of Free real RAM & my VM is at 26GB of Disk space now.
Your Mac needs adequate hard drive space to operate normally. How full can a drive be before it's too full? There is no hard and fast rule that says “X” amount or “%” of free drive space is needed. A low amount of RAM requires more drive space for Virtual Memory’s swap files. As a general rule, your available space should be 5GB as an absolute minimum as it generally requires that much free space to perform an Archive and Install of Mac OS X and still preserve some free space for VM swap files.
Here is the not "hard and fast" rule. If your computer's HDD is 40 GB or less you need to maintain a minimum of 5 GB as contiguous (unfragmented) free space. HDDs over 40 GB need a minimum of 15% of total disk capacity as contiguous free space. Yes, part of the function of free space is for swap files. More critical, however, is maintaining free space to allow the Extent Overflow File in the directory to lay down new pieces of the file as that data on the drive increases. Without that much contiguous free space you can end up with directory corruption as the Extents Overflow File begins overwriting extents that already have data on it. You then end up with overlapping volume structures which can only be corrected by removing data from overlapping extents so that there is only one piece of data on those extents. The pieces of data that are removed are deleted, so your data files may become irretrievably damaged.
I suggest that you maintain 20% of total capacity as free space to be sure there is enough
contiguous free space. In your case, sounds like your computing habits dictate a larger capacity HDD. I suggest that you make a full backup/clone of your HDD immediately and install a larger capacity HDD.
