Tip: Using smaller block allocation size to save disk space

From Friday May 30th

By default, the minimum disk allocation block in Mac OS X is 4 KB. This means that the minimum size of any file will be 4 KB. This was not a serious issue under Mac OS 9, but a standard Mac OS X installation consists of tens of thousands of often extremely small files.

MacFixIt reader David Butler describes his process for re-claiming disk space via setting a lower allocation size:

"Although I was a bit leery of using third-party hard-disk drivers, it was the only way I could think of to change the minimum allocation block size. I booted into Mac OS 9 from a custom boot CD on which I put the latest version of Silver Lining. I then reformatted the 3 gig drive using a minimum allocation block of only 512 bytes (the smallest setting). Afterwards, I reinstalled Jaguar without difficulty, and found that I had saved approximately 600 megabytes of drive space. That's a considerably amount of space "wasted" by OS X and the associated default applications alone. The drive, and the iBook, have been working properly for many months, and I've since done the same thing to my other iBook with a 10 gig drive (which also continues to work properly)."

Feedback? Late-breakers@macfixit.com.

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