Op 23/05/2008 om 15:57:52 +0100, schreef Jonathan Thornburg : > > I would like to have more than one openbsd root filesystem on my > > hardrive. Could somebody please explain how to go about this? > [[...]] > > Using openbsd I could use multiple bios-partitions each having an a: label > > but how do I tel the bootloader to use a specific partition? > > I have kept two copies of OpenBSD on my laptop for a long time (going > back to 2.8, I think). I've described my scheme in this list several > times, eg <http://archives.neohapsis.com/archives/openbsd/2005-05/1384.html>.
I like it. > Basically I keep a single fdisk partition containing the entire disk, > but two sets of OpenBSD root, usr, and now var partitions inside that, > both sharing /home and /data (where I keep my user files): > wd0a root fstab mounts root, usr, var, home, data > wd0b swap > wd0c entire disk > wd0d root2 fstab mounts root2, usr2, var2, home, data > wd0e var > wd0f var2 > wd0g usr > wd0h usr2 > wd0j home > wd0k data > > I use the standard OpenBSD bootloader; typing "boot wd0a:/bsd" > (or just doing nothing and waiting for the 5 second default timeout) > boots the wd0[aeg] set of partitions, while "boot wd0d:/bsd" boots > the wd0[dfh] partitions. > > I normally boot & run from the wd0[aeg] partitions; currently these > contain OpenBSD 4.3-release, while wd0[dfh] contain 4.2-stable. When > I do an OS upgrade or reinstall, I only do one of the two sets of > partitions, leaving the other unchanged as a backup. For example, > prior to a few weeks ago, both partition sets contained 4.2-stable; > when I was ready to install 4.3-release I first copied (dump|restore > and then running installboot on the wd0d /boot) the wd0[aeg] partitions > to the wd0[dfh] partitions, and verified that I could boot & run > normally from the wd0[dfh] partitions. (In fact, as a test I ran > from them for 5 days or so before finally doing the 4.3-release > install.) This way if anything had gone wrong with the 4.3-release > install (nothing did), I could have aborted and rebooted from the > wd0[dfh] ones and (still) had a working computer. This is still pretty obtrusive, i.e. making a backup, then overwrite filesystems you normally use, hoping the backup is a copy you can rely on. This would all be unnecessary if the bootloader could be informed that it should boot from wd0d:/bsd from now on, so you could leave wd0a: et. all unharmed. Is there really no way to do that, other than by typing it on the boot prompt? Alternatively, is there a way to safely switch labels in the labeleditor, so that wd0a would become wd0d and vice versa? -- Leo Baltus
