Subject: Re: Migration question( OpenBSD 2.9 -> NetBSD -current)
To: Milos Urbanek <urbanek@openbsd.cz>
From: Luke Mewburn <lukem@wasabisystems.com>
List: current-users
Date: 05/02/2002 09:47:14
On Wed, May 01, 2002 at 11:26:02PM +0200, Milos Urbanek wrote:
  | On Wed, May 01, 2002 at 10:57:48AM -0700, Bruno Saverio Delbono wrote:
  | > Hello guyz,
  | > 
  | >     I have two 30 GB drives serving as one raid0 device currently on
  | > my OpenBSD box. Due to many reasons, I want to upgrade to NetBSD
  | > -current. However, I have a question:
  | > 
  | > Can I maintain or preserve all the data on two disks (serving as raid0)
  | > during reinstall or can I save it?
  | 
  | 
  | My experience is that although NetBSD and OpenBSD use ffs fs, there are
  | some subtle differences that cause the NetBSD not to be able to mount ffs
  | partitions created under OpenBSD.
  | More specifically, under NetBSD current (e.g. 1.5ZC) you can mount
  | ffs partition from OpenBSD 3.0, but when you do a 'ls' or another
  | fs operation on it you will get an EBADF error if I'm correct.

This is interesting.  Do you have any further details?  Does NetBSD
current's fsck_ffs (with -n to "not change" the file system) work
on the OpenBSD ffs partitions?

A while ago I took pains to ensure that the ffs superblock in NetBSD
would be compatible with FreeBSD's and OpenBSD's, so that explains why
the mount worked ok.  I also took a brief look at other changes in ffs
on those systems at the time and I don't recall anything that would be
done to make things difficult.

If possible, I would like for NetBSD to be able to mount FreeBSD and
OpenBSD ffs partitions (there really should be no need for gratitious
incompability here, especially if we're not using newer features such
as snapshots on the partition, as all three systems are relatively
"close" in this way), and possibly other platforms such as MacOS X,
Solaris, etc.


  | Therefore I would suggest you to do a full backup (e.g. using tar) and than
  | reinitialize your disks by fresh NetBSD-like raid/ffs partitions.
  | 
  | Milos

-- 
Luke Mewburn  <lukem@wasabisystems.com>  http://www.wasabisystems.com
Luke Mewburn     <lukem@netbsd.org>      http://www.netbsd.org
Wasabi Systems - NetBSD hackers for hire
NetBSD - the world's most portable UNIX-like operating system