LUN 256

Hi Hulk,

I think you should look into Dynamic Lun Addressing, not device offset.
See the Technote "Symmetrix Dynamic LUN Addressing" available on http://powerlink.emc.com
Navigate as follows:

Home > Support > Technical Documentation and Advisories > Hardware/Platforms Documentation > Symmetrix DMX Family > Symmetrix DMX-3 > Technical Notes/Troubleshooting >

Benevolent Moderator:
Or, go directly to the above ref. doc at
http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Documentation/300-005-734.pdf

Message was edited by:
DJY; added direct link

In my experience I have only seen LUN offset used in OpenVMS environments where one host access devices on two different symms. You would offset the LUNs on one of the Symms in order to distinguish between the two arrays.

I'm sure there are other uses though, haven't read up on it in a while.

Thanks....

okay.. so I wld use dynamic lun address.

so what is LUN offset? and where is it used.?

We used it often with Solaris hosts. You can map more then 256 luns on any FA port. But Solaris refuses to "see" luns above 255. Thus we used the lun offset trick and mapped (just an example) 512 luns on a single port, offering the first 256 to a single host and the other 256 to another different host.

DLA replaces the good old lun offset trick thus you probably don't need lun offset.

I have gone through this thread in symmetrix

https://forums.emc.com/forums/thread.jspa?threadID=67721&start=0&tstart=10

so I believe if we set the DLA for a wwn we must always use DLA for that wwn.

but we have storage provisioned from multiple symm and their LUN address have not reached 256.

how do we reclaim this dev which has provisioned to host as DLA. Is it same as normal un masking?

enabling DLA on one Symm should not affect devices on another symm because they are on different targets as far as the host is concerned. Yes, once you enable DLA you have to use it from that point forward, but really there is nothing special you need to do other than remember to add -dynamic_lun option to your masking command. Looking at manual pages for symmask, you don't have to do anything special for unmasking ..just your regular "remove dev" command.