The 1024 cylinder limit is not the only reason to seperate /boot and /. I like a /boot around 16MB, 2 cylinders on an LBA disk.
Think about your systems operation, once it's up. A number of my machines serve web pages, which is partly largish image files, and /usr tends to be fairly large. As an optimisation, those image files go on the outer edges of the platters, with the highest transfer rates. As the files systems are large, there will be fair amount of seeking no matter what, so they're on the edge of the disk. Systems like /, are rightly kept as static as possible, root corruption after power failure, is not fun, and precautions such as seperating out /tmp and /var are worthwhile. The other reason is security, a number of exploits have involved making hard links in public writeable areas, eg) /tmp and /var/tmp. Traditionally /tmp would be agressively cleared out, perhaps rebuilt after a reboot, and /var/tmp was used by programs like vi(1) which use recovery files, that need to survive a reboot. The waters became muddied, as /var with log, spool and tmp all with the potential to become large, would often on servers be moved off to a quieter disk, in a large file system to itself. The directory your temporary files are written can be controlled by environmental variable, IIRC TMPDIR, see C library routines like tmpnam(3) for details. The system default directory is actually determined by the C library, it's policy, user space issue not a kernel decision. On systems by Sun, /tmp defaults to be implemented on top of the VM system, using the swap space if files get left around, or are too large for RAM. There are pro's and con's, the material makes for good flame bait, personally I found it _did_ speed up compiles and things, working a little like a RAM disk, at the risk of denial of service attacks, due to VM clogged up with large temporary files. As a few programs may use /var/tmp rather than $TMPDIR (/tmp default), or both, and expect them to be different, I would suggest having seperate directories for /tmp and /var/tmp, even if you wish to share one filesystem, possbily on another disk for speed reasons. Finally to write and read small temporary files quickly, lets keep them in the centre of the disk, with lots of free blocks to avoid fragementation. But not so large that lots of seeking takes place. Thus the partition layout goes something like : /boot /images /usr / /tmp /var /home /less_frequently_used_data /rarely_used_stuff Rob
