Questions re: disklabel for external USB drives

[Jerry McAllister]

On Mon, Dec 11, 2006 at 02:26:42PM -0500, up at 3.am wrote:

> On Mon, 11 Dec 2006, Jerry McAllister wrote:
> 
> > On Mon, Dec 11, 2006 at 02:05:27PM -0500, up at 3.am wrote:
> >
> > >
> > > I just got an external USB drive that I want to use for disk-based
> > > backups.  It is important that this drive be useable on different FreeBSD
> > > servers that we have.
> > >
> > > I got it working on a test server ok, but I noticed that the sysinstall
> > > utility labeled the device as:
> > >
> > > /dev/da0s1d
> > >
> > > Since the test server only has an IDE drive, that's fine, but this
> > > external USB drive needs to be able to work on productions servers that
> > > already have SCSI and SAS devices, one of which already uses that label
> > > for its active "/usr" partition.
> > >
> > > Is there an easy way to force the device to work as something like:
> > >
> > > /dev/da1s1d
> > >
> > > on all of the servers, including ones that do not already have a SCSI disk
> > > subsystem and existing /dev/da0 devices?
> >
> > You don't have to do that unless you are worried about getting confused.
> > If you put the drive on a machine that already has da0 used up, it will
> > magically become da1.   The label doesn't have anything to do with
> > whether it is da0 or da1.   That is determined by its position on the
> > controller.
> >
> > I think, in FreeBSD SCSI device stuff, you can force it to be
> > something, but I have never done it and don't know how - and since
> > it doesn't matter, don't see the reason to try.
> >
> > ////jerry
> 
> Cool!  Thanks!

Of course, you have to keep track of the different device labels
when you mount the file systems and/or put them in /etc/fstab on
whichever machine so they mount the right device for that machine.

////jerry

> 
> James Smallacombe		      PlantageNet, Inc. CEO and Janitor
> up at 3.am							    http://3.am
> =========================================================================
>