Recently installed FreeBSD on a new system. It allocated 384M (the
default, apparently) for the / partition. I then rebuilt the kernel.
During installation of a new kernel (using "make installkernel" from
/usr/src) FreeBSD backs up the old one and then installs the new one.
FreeBSD has apparently grown, because installation of the new kernel
(including symbols and kernel modules) overflowed the partition.
There's no way to adjust partition sizes easily in FreeBSD, so it's
not possible to rebuild the kernel unless one foregoes generating
symbols (which can make debugging difficult).
Change sysinstall to allocate enough room in / to allow rebuilding of
the kernel with backup of the original (GENERIC) kernel. Before each
release, verify that the default size of / does not need to be increased
to allow this.
How-To-Repeat: Install FreeBSD 8.1. Make a custom kernel. Install it.
sysinstall has been replaced by bsdinstall in FreeBSD 9.x. Closing.