In another thread,
bsd-keith asked:
Quote:
Originally Posted by bsd-keith
I'd be tempted to grab the install disk/image & do an 'upgrade' - would that be wrong?
|
There's nothing wrong with booting installation media. But it isn't strictly necessary. That's because once you have boot blocks on a disk drive, you can use it to boot
any valid kernel. The boot.conf(5) man page for your architecture explains how to select an alternate kernel.
Installation media -- CD-ROM, diskette, USB stick -- have boot blocks which boot the RAMDISK kernel. This is
bsd.rd or, if on diskette, the same kernel with a smaller set of device drivers so it will fit in the space required. Even your local network can act as bootable installation "media", see diskless(8), and for amd64 or i368, see pxeboot(8).
The RAMDISK kernel contains a root filesystem in RAM, and the install and upgrade scripts, and can be used for reinstallation, upgrade, rescue, or root filesystem maintenance that cannot be performed while the "real" root filesystem is mounted. The
bsd.rd kernel is installed along with any other kernels during installation, so it is always available for rescue, maintenance, or reinstallation.
To conduct an upgrade to the next sequential -release, or to a snapshot, you only need to download the appropriate
bsd.rd and select it at boot time. On i386 or amd64, you can even switch architectures, if the CPU supports both, but you would need to reinstall. You cannot upgrade and switch architectures at the same time. Binary executables will not run on multiple architectures.