*If you’re talking about OSA-ICC consoles, then the physical port can be shared between LPARs, and two LPARs can have the same device numbers sharing that port, but they are still unique logical devices and have different TN3270 LU names*
For every device , there has to be a UCW in HSA . If the ports can be shared between lpars , how are they going to be physically different ? Agree that they are unique logical devices (UCB ) on each LPAR . But that doesn't mean they have to be physically different . For shared devices , can't they have different UCB's per OS , but map to the same UCW in HSA ? Linda On Wed, Jun 8, 2016 at 2:40 AM, baby eklavya <baby.ekla...@gmail.com> wrote: > Thank you John and Curtis for the explanation . > > > Infact , I should have said UCW instead of UCB to make it more clear . But > now i understand that they could be physically different devices . > > > > > On Wed, Jun 8, 2016 at 2:09 AM, Pew, Curtis G < > curtis....@austin.utexas.edu> > wrote: > > > On Jun 7, 2016, at 3:08 PM, baby eklavya <baby.ekla...@gmail.com> wrote: > > > > > > To my understanding , when sharing MCS consoles in a sysplex , one > thing > > > which matters is the console name which has to be unique for each LPAR > > even > > > though the UCB can be the same . Then again , console uses EXCP to > write > > > the screen of data each time . Since the UCB is shared , how does it > > > actually work ? > > > > > > Unlike DASD devices which goes via SSCH logic in which the device busy > > > status is checked when applications from multiple LPARS try to write on > > the > > > same UCB ,the console seems to be working in a different way in a > > sysplex . > > > > > > I have been searching on this for a while , but couldn't find anything > > > documented about this so far . Can someone clarify /guide me where i > can > > > find this information ? > > > > I think you’re confused. UCB’s are not shared between LPARs; a UCB is a > > control block (that’s the ‘CB’ part of ‘UCB’) managed by MVS within the > > LPAR’s storage, so it can’t be shared. > > > > If you’re talking about OSA-ICC consoles, then the physical port can be > > shared between LPARs, and two LPARs can have the same device numbers > > sharing that port, but they are still unique logical devices and have > > different TN3270 LU names. In the OSA configuration you map TN3270 LU > names > > to unique LPAR/device number pairs. Here’s an extract from on of the OSA > > configurations on my system: > > > > <CONFIG_SESSION> > > <SESSION1> > > CSS= 00 IID= 01 DEVICE= 0200 > > GROUP= "PC200" > > CONSOLE_TYPE= 2 RESPONSE= OFF READ_TIMEOUT= 60 > > </SESSION1> > > > > … > > <SESSION17> > > CSS= 00 IID= 02 DEVICE= 0200 > > GROUP= "T1C200" > > CONSOLE_TYPE= 2 RESPONSE= OFF READ_TIMEOUT= 60 > > </SESSION17> > > > > > > If I configure my tn3270 client to connect to LU “PC200” it will connect > > to device number 200 on the LPAR with id 01, while if I configure it for > LU > > “T2C200” it will connect to device number 200 on the LPAR with id 02. The > > only thing being shared here is the physical port (and its IP address) > and, > > on the other end, the device number. But they are two distinct logical > > devices, and each has its own UCB managed by the instance of z/OS in the > > appropriate LPAR. > > > > (I guess another thing that might be confusing about this is that if you > > look at HCD you’ll only see one device with device number 200, apparently > > “shared” by the LPARs. But all that’s really being shared is the physical > > port and the device number.) > > > > -- > > Pew, Curtis G > > curtis....@austin.utexas.edu > > ITS Systems/Core/Administrative Services > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
