Hi Mark,
When you say the "real" LUN number, are you referring to the SVC's MDISK
LUN ID, which is representing the backing storage? If so, I do not
believe any host OS has the ability to see these identifiers, as the SVC
only uses that internally, as part of his MDISK-to-VDISK mapping. This is
because the data itself can be moved from one (or more) physical LUNs to
others as part of data migration or balancing or what-have-you, and so
these LUN identifiers are not interesting to the host. (For the record,
"MDISK" is SVC's term for Managed Disk. It is not to be confused with the
minidisk definition of MDISK that is common in VM.)
The VDISKs themselves are mapped to the connected hosts, and it is the
resulting LUN identifier for these devices that the OS will see in the
form of x000A000000000000 or whatever. In the VDISK-to-Host mapping panel
of the SVC console, there is a "SCSI ID" column (at least in the version I
have available to me), that is the **decimal** value of that LUN ID.
Regards,
Eric
Eric Farman
z/VM I/O Development
IBM Endicott, NY
(607)429-4958 (tie 620)
From:
"Wiggins, Mark" <[email protected]>
To:
[email protected]
Date:
05/25/2010 03:46 PM
Subject:
Mapping an Emulated DASD device to an SVC LUN number
Sent by:
The IBM z/VM Operating System <[email protected]>
We’re looking to migrate to a new z/10 and we’ve come up with an issue
that hoping someone out there knows how to resolve. A while back when we
installed our SVC (2145) we lost the ability to see the “real” LUN number
that was being assigned to our z/VM system as an emulated (9336) device.
On the SVC side on things you see a 16 character LIN id like this;
000000000000013D (which we’d only use the last 4 of “015E”). When you run
the SCSIDISC command on z/VM, the LUN that shows up in z/VM in just the
next number in sequential order (e.g. if it was the 11 LUN allocated, it
would have a LUN id of 000A000000000000). Are there any commands from z/VM
that can be issued to give you the LUN id as defined within the SVC? A
command like “q edev e011 details” shows
EDEV E011 TYPE FBA ATTRIBUTES 2145
VENDOR: IBM PRODUCT : 2145 REVISION: 0000
BLOCKSIZE: 512 NUMBER OF BLOCKS: 83886080
PATHS:
FCP_DEV: A200 WWPN: 50050768011035EE LUN:
000A000000000000 PREF
CONNECTION TYPE: SWITCHED
Mark Wiggins
University of Connecticut
860-486-2792
