Looks like somebody forgot to read man pages..
Quote:
|
Originally Posted by newfs(8)
-m free-space
The percentage of space reserved from normal users; the minimum free space threshold. The default value used is defined by MINFREE from <ufs/ffs/fs.h>, currently 8%. See tunefs(8) for more details on how to set this option.
|
In this case; 285 * 8 is 2280... add a decimal point, 22.8G.. or something.. math isn't my expertise, but it clearly accounts for some of the missing space you're noticing.
Also, a portion is used for file system metadata.. i.e: inode structures.