For really large file systems or for small memory machines, the algorithms in fsck_ffs will inevitably run out of memory. It appears that there are two possibilities to deal with this: 1) multiple sub-passes over the file system, dealing with parts of the data each time
2) modifying the ffs on-disk structure to add enough space reserved for fsck to store needed information during its run There may be more, but I believe that in the long run something on the order of 1 or 2 will be necessary. I have some ideas about how to implement either one if there's any interest. Otherwise it'll wait until the indefinite future. geoff steckel