> Sent: Friday, September 28, 2018 at 9:04 PM > From: "Don NetBSD" <netbsd-embed...@gmx.com> > To: netbsd-users@netbsd.org > Subject: Re: BSD disklabel partition letters in NetBSD
[...] Hi and sorry for the delay! > > Remember, the partitions have no knowledge of where they actually exist in a > FILESYSTEM! Yes, of course. > So, in a degenerate example, put 2 partitions on a disk that each represent > an entire root filesystem TO THE OS THAT IS BOOTED. This is exactly the degenerate example I wanted to refer to. Let's consider a BSD disklabel in the first sector of a hard disk (so, without MBR) with the following partitions defined: a: /, root partition of system A b: unused c: unused (in some cases, it represents the whole disk) d: unused e: /homeA, home partition of system A f: swap partition of system A g: /, root partition of system B h: /homeB, home partition of system B i: swap partition of system B Let both system A and B be NetBSD, for example 8.0 e 7.1, so we are sure that they are both fully-compatible with the BSD disklabel layout. Now, boot system A from partition `a'. First: is it possible to do so? Then, how would partitions `g', `h' and `i' be detected? In other words, what would the output of `disklabel wd0' be from system A? Ideally, at least partitions `g' and `h' should be mounted, fully readable and writeable. But as regards mountpoints, there is some confusion, given that partition `g' should be mounted in the same place as the already mounted partition `a'. Or does this only depend on how fstab(5) has been set up? Then, boot system B from partition `g'. Same questions as above. > I think you can actually get even messier if you use an MBR to create 4 > different MBR "slices" -- and put NetBSD labels *in* each of those defining > 4/8/16 different "NetBSD partitions". Then boot some particular NetBSD > partition from that set of 4/8/16 available! This would be extreme :). > Sorry to further complicate the discussion by drawing a distinction between > MBR /slices/ (which the rest of the world calls a /partition/) and NetBSD > /partitions/ within said slice(s). Don't worry, I know this distinction, it's maybe the easier thing here! Thank you :), Rocky
