The onliy time you need to partition like that is if you're doing experimental stuff, and you don't know how it's going to react. Under normal operations, your log files won't grow very fast, and cleanup fron cron will always happen. I've got 2 partitons situated as such:
swap 128M
/ 4Gig-swap size (I was never good at calculating space ;-) )
Of course I have other space to utilize, my samba shares usually have their own drives, and customer's sites, email spools, and miscellaneous data are all on thier own drives... |