LUN masking and zoning question.

[stephen2615]

Hi all,

If my storage array presents a number of LUNs/LDEVs down two physical fibre cables which are outputs from the primary and secondary controllers, and those two cables are ports on the MDS switches, do you need to know the LUN number as it was created on the array?

I read the Fabric Manager Configuration Guide and it talks about LUN masking at the array. It says to check the Check LUN box. I have not tried this so I was wondering if the LUNs on the array will appear for me to select. If there are say 8 LUNs presented (4 primary and 4 secondary), are they visible when using this option?

I have a fair sized number of new blades with HBA's with dual ports that need to connect to a large HP array. The setup will be one path goes from a 9216 to a 9509 via port channels (and another path through a similiar setup) to the HP array which will be presenting LUNs through LUN masking to the individual WWN's of the blade HBAs ports. There will be literally hundreds of LUNS coming out of the array so if they are presented in Fabric Manager, it would make my life easier especially when the array is looked after by HP and they might not be around when I start configuring the SAN.

Thats the joy of outsourcing.

Any help would be very welcome.

Regards

Stephen

[tblancha]

Finding out what LUNs are available is done via SCSI commands INQUIRY and REPORT_LUNS. In general, having the MDS discover the luns is not done since the MDS does not need to know. The end devices that are zoned and configured in the array's LUN security will need to know and they will use the two above frames to find this info out. The check luns checkbox that you reference is when doing LUN zoning (which is part of Enterprise license). In fact, the manner in which we are able to zone based upon a LUN is by trapping and manipulating the REPORT_LUNS frame. A generic implementation is to simply zone an initiator and a target via their PWWN's. Then, in the array, there is a security mechanism that allows the PWWN of a device to access a particular LUN. That LUN is then associated with a particular volume of disk space. However, we offer the capability to zone with the granularity of the LUN/PWWN combination if you so desire it.

[stephen2615]

Hi Timothy,

I value your advice and hopefully aspire to be as knowledgable as you one day.

We have typically not done LUN masking because we used dedicated storage and SAN islands. Now that we have a whole bunch of large storage arrays, it is something that I have to come to grips with.

Our project manager did not buy any licences with the MDS switches because he obviously did not know he had to and no one consulted me. I blame the vendor for that.

If we had an enterprise licence, could I then select the particular LUN from the storage array via the check box? Basically I am trying to make my life a bit less complex especially when dealing with outsourcers.

Regards

Stephen