Lets imagine a new rack server or a new blade server has been added to your Fibre Channel SAN. The first job for the SAN administrator is to zone it to the storage it requires access to. The task normally runs something like this:
- Identify the WWPNs for the new server HBA. We can do this using Qlogic SAN Surfer or Emulex HBAnywhere, or by looking at the WWPNs reported by the Fibre Channel switch or by using datapath query wwpn (with SDD and SDDDSM) or by using the xiv_fc_admin -P command with the XIV HAK. There are lots of different ways, you get the idea.
- On fabric 1 create a new alias for the server HBA port cabled to that fabric.
- For each storage device that the server needs access to on fabric 1 (or possibly just switch 1), create a new zone and include the new server alias and the alias for every relevant storage port on that device. Repeat if you have other storage devices (so two XIVs means two new zones).
- Put the new zone (or zones) into the active zoneset (or a clone of it) and activate it.
- Repeat on fabric 2 (after waiting a decent interval to ensure no mistakes were made in fabric 1... well I hope you wait.... you do don't you?).
The main trap here is that when creating a zone, you need to ensure you select all of the correct storage aliases for your selected storage device. For instance we could have a simple layout like this:
Fabric 1 contains our new server (in this example an IBM x3850) and three XIV ports:
This means when creating the zone I need to identify and select four separate aliases. What I could do instead is create an alias with all my XIV target ports in it. Now I only have two aliases to select in that fabric:
50:01:73:80:0e:b0:01:40; 50:01:73:80:0e:b0:01:60; 50:01:73:80:0e:b0:01:80
If this was a Storwize V7000 implementation I could do the same thing. A typical install often look like this, where fabric 1 contains our new server and two Storwize V7000 ports:
This means when creating the zone I need to identify and select three separate aliases. What I could do instead is create an alias with both my Storwize V7000 WWPNs in it. Now I only have two aliases to select in that fabric:
This method of amalgamating multiple storage port aliases works fine for devices like DS8000, SVC, Storwize V7000 and XIV. I use this method all the time to simplify zoning and I find it reduces both mistakes and the time required to complete zoning tasks.
The only exceptions are:
- Don't do it for DS3000, DS4000, DS5000 or DCS3700 as the controllers on these devices do not like to see each other through the switch.
- Don't combine ports from different storage devices, so if you have two XIVs in a fabric create one alias for the target ports of each XIV (although you could combine ports from different SVC I/O groups within the same SVC cluster into one alias). You should still use individual aliases for ports being used for migration or replication purposes.
- Don't use the WWNN to create an alias. Always create multi-WWPN aliases so you have granular control of which ports go into the alias. If you use the WWNN from an XIV you will also implicitly include any ports that are being used for replication or migration and thus zone them to the host, which makes no sense.
I would love to hear any techniques you have to make your (and my) life easier.