Every now and then people ask how they should partition their hard disk, this doesn't answer that question, but gives some view on how much disk space is used up on a bare system built for compiling OpenBSD from source.
Reference OpenBSD 4.9 i386, FAQ 5
The following is a summary of disk space used on a bare install built for and after compiling OpenBSD 4.9 i386. No packages installed.
|/etc||60M||Bare install, no modifications|
|/usr||6.0G||STABLE source extracted to src, xenocara, and compiled using ./obj, ./xobj, as well as ./rel for release files, and ./dest for pre-release files|
|/usr/src||851M||includes compiled kernel GENERIC.MP|
|/usr/ports||332M||No compiled packages, no distfiles|
|$DESTDIR||2G||/usr/dest Includes cvs export for src, xenocara, and ports|
|$RELEASEDIR||500M||/usr/rel Includes tgz source for src, xenocara, ports|
|$CVSROOT||4.4G||CVS Tree scp'd from another server/workstation.|
|$CDBUILD||1.1G||Contains pre-build CD directory and install.iso created with mkhybrid(8) (no packages) approximately 490MB each|