Thanks for the tip.  Yes, it really is LUN-0 that is missing.  All the
other LUNs (1-6) do show up in this error condition, and upon reboot
they all show up.  It is only an occasional boot up where I see LUN-0
missing, and I wanted to avoid a reboot to restore it.  I'll give the
re-scan trigger a try and see if LUN-0 shows up.

What is the magic with the "- - -" that triggers the scan?  A bit of
searching shows that many other people know about this, but I've
somehow missed it. Is there any documentation that describes this
interface (didn't see anything in the kernel docs)?


On Mar 25, 7:27 am, Konrad Rzeszutek <> wrote:
> On Wed, Mar 25, 2009 at 08:26:46AM +0100, Ulrich Windl wrote:
> > On 24 Mar 2009 at 19:47, agspoon wrote:
> > > We have an occasional problem where one LUN of a target (LUN-0) does
> > > not appear in a connection started by iscsistart.  This is in an iscsi-
> > > root scenario where iscsistart is called from within the initrd
> > > ramdisk image.  I don't why this happens, but I can detect when it
> > > does.  However, I don't know how to stop the connection and try
> > > again.  If I just re-run iscsistart, it complains that there is
> > > already a connection.  I tried just pulling out all the iscsi related
> > > modules and re-loading them, but they are "in use".
> > Hi!
> > I think that's not very iSCSI related, so my guess would be to keep the 
> > connection
> > and try a "rescan SCSI bus" on the SCSI host/connection that you already 
> > have.
> > Also, do you really need LUN 0? Disks are usually assigned to a LUN != 0.
> They are with some iSCSI targets (MD3000i, DS3300, AX150, CX300, Compelant, 
> DataCore,
> and some other ones).
> Do you have any other LUNs on the target except LUN-0? Do they show up?
> If not, you can do 'echo "- - -" > /sys/class/scsi_host/hostX/scan" to
> retrigger the scan. That should make the LUN-0 and others show up.
> You will have to figure out the hostX relation to 
> /sys/class/iscsi_session/sessionY
> yourself.
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