Re: Raidctl -u ought to turn off autoconfigure on the target raid set

[Greg Oster <oster%cs.usask.ca@localhost>]

Manuel Bouyer writes:
> On Tue, Aug 26, 2008 at 09:54:44AM -0700, Brian Buhrow wrote:
> >     Hello.  I'm not sure if I should file this as a PR or simply make the
> > suggestion on the mailing lists.
> >     When raidctl -u is run against a raid set which has auto-configure
> > turned on, it really ought to first turn off autoconfigure on that raid set
> > before it unconfigures the raid set.  Otherwise, if you reboot the system,
> > the old raid set becomes a participant in the night of the living dead.
> > This can be a problem if you're trying to migrate from one image to another
> > by breaking a mirrored raid set, putting a new image on one of the disks,
> > configuring a new raid set with the newly imaged disk as the working
> > component, then rebooting to that new image and adding  the disk with the
> > old image to the new raid set and thus completing your upgrade.  When you
> > reboot, if the old disk is part of the original mirrored raid set, and the
> > new disk is part of a new raid set, you automatically boot to the old image
> > again.  Also, while it's possible to run raidctl -A no manualy before
> > unconfiguring the raid set, it would be nice not to have to remember that
> > step, or discover that you forgot it the hard way.
> 
> If you really want to remove it permanently, just do
> raidctl -A no ...
> becore
> raidctl -u ...
> 
> It can be handy to temporary unconfigure a raid device, and have it show
> up again after reboot.

"What he said."  Perhaps a "raidctl -U" (for "Unconfigure and wipe 
component labels") would be more useful for what you want...  
Of course, that starts getting dangerous in terms of what can get nuked 
by a simple mistake... 

Later...

Greg Oster