On Tue, Dec 17, 2013 at 5:10 AM, Shawn K. Quinn <[email protected]> wrote: > On Mon, Dec 16, 2013, at 05:26 PM, Donald Allen wrote: >> On Mon, Dec 16, 2013 at 5:48 PM, Tekk <[email protected]> wrote: >> > I've got an ext3 /home partition which I use under linux, how likely is >> > it that files will get clobbered if I use the same /home under a dual >> > boot with openbsd? >> > >> >> Your subject asks about the stability of the ext2 support in OpenBSD, >> but your message says you have an ext3 partition you want to access. >> ext2 and ext3 are not the same thing -- ext3 is a journaled variant of >> ext2 that OpenBSD does not support. See >> >> http://www.openbsd.org/faq/faq9.html >> >> Don't do it. > > My understanding is read/write access is considerably more risky than > read-only access. If you just need to read that /home under OpenBSD it's > much less complicated and less risky as you can just mount /home > read-only and be done with it (even if it's still ext3). > > At minimum, if you insist on read-write, you should get rid of the > journal thus converting ext3 back to ext2. It's a Really Bad Idea to > mount ext3 as ext2 read-write unless you are extra careful to shut down > cleanly every time and even then it's dubious. > > It *might* be less risky if you format that /home as FFS and access it > using the Linux kernel's UFS/FFS module. Or, you could simply keep > separate /home for GNU/Linux and OpenBSD, which to me is perhaps the > cleanest solution. (I tend to compile a lot of stuff and install it to > $HOME/bin when I don't want it cluttering up /usr/local/bin which is > something I will admit a lot of users probably don't do.)
ext2 is a side line for OpenBSD, not used as much and therefore not as well-tested as the ffs code. The same is true for Linux, exchanging ext2 and ffs. I'd be very disinclined to trust a file-system I cared about to code that hasn't been heavily beaten upon. I learned this the hard way when I encountered a bug in FreeBSD's ext2 support that killed the system and damaged the file-system. This was some years ago, but as I recall, I had to resort to using Linux's fsck to put things back together. The original post implies that he wants write access to the file-system from both OpenBSD and Linux, so mounting read-only probably doesn't serve his purpose. It he converts his ext3 file-system to ext2, then he can mount read-write with OpenBSD, assuming the OpenBSD ext2 code supports 256-byte inodes, and run the risk of discovering a bug in the OpenBSD ext2 code. And he loses the protection of the journal when running Linux. I think your suggestion of separate /home file-systems makes the most sense. > > -- > Shawn K. Quinn > [email protected]
