Re: RAID superblock confusion

Richard Gooch (rgooch@ras.ucalgary.ca)
Wed, 10 Apr 2002 16:49:06 -0600


Mike Fedyk writes:
> 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.

Exactly where is this? A scan with find and grep don't reveal this.

> Ever since I have had raid compiled into my kernels.

This is my relevant .config:
CONFIG_MD=y
CONFIG_BLK_DEV_MD=y
CONFIG_MD_LINEAR=m
CONFIG_MD_RAID0=m
CONFIG_MD_RAID1=m
CONFIG_MD_RAID5=m
CONFIG_MD_MULTIPATH=m

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/