On Mon, Oct 21, 2002 at 09:19:12PM +0530, MShetty wrote:

Hi,

Thanks a lot for all the replies

A piece of code I am reading, sends the Inquiry cmd to lun 0 first and then to
the actual lun to be probed. As only SCSI devices have the concept of luns... I
think the 1st probe to lun 0 is to check if it is a SCSI device but... on 2nd
thought the same can be inferred by probing for lun n.

No.  SCSI devices, if present on a given target, must have something on 
LUN 0.  That item on LUN 0 doesn't have to be online, but it has to exist 
and respond to the INQUIRY command.  LUNs > 0 need not exist.

I have read something which says that some devices may mess up if probed for
luns > 0. Is this true ??

Yes.  Absolutely.  Lots of CD-ROM drives will hard lock when you try and 
probe for LUNs > 0.

-- 
  Doug Ledford [off-list ref]     919-754-3700 x44233
         Red Hat, Inc. 
         1801 Varsity Dr.
         Raleigh, NC 27606