Re: RAID superblock confusion

[Mike Fedyk <mfedyk@matchmail.com>]

On Wed, Apr 10, 2002 at 03:39:09PM -0600, Richard Gooch wrote:
> Mike Fedyk writes:
> > On Wed, Apr 10, 2002 at 02:37:48PM -0600, Richard Gooch wrote:
> > > 
> > > The device is set up (i.e. SCSI host driver is loaded) long before I
> > > do raidstart /dev/md/0
> > 
> > But kernel auto-detection doesn't depend on the raidstart command.  If
> > things are setup correctly, you can remove that from your init scripts.
> 
> I'm not (explicitely) using auto-detection. When I insmod the raid0
> module, there are no messages about finding devices. All I get is:
> md: raid0 personality registered as nr 2
> 
> Only when I run raidstart do I get kernel messages about the devices.
> 
> In any case, I should be able to move my devices around (especially
> if /etc/raidtab is still correct), whether or not autostart is
> running. The behaviour I'm observing is a bug (I assume it's not a
> mis-feature, since the raidstart man page tells me that moving devices
> around should be safe).

Ehh, I ran into this a while ago.  When you compile raid as modules it
doesn't use the raid superblocks for anything except for verification.  I
took a quick glance at the source and the auto-detect code is ifdefed out if
you compiled as a module.

Ever since I have had raid compiled into my kernels.

Mike