Wednesday, July 3, 2013

Enhanced Zoning - (Storage Series Part-6)

FC Aliases

- FC Aliases gives user friendly names to the WWNs, FCIDs etc and are analogous to DNS in IP

- Syntex - fcalias name

- Alias can be advertised through Zoneset distribution. Syntex - zoneset distribute vsan 1

- Example:

 fcalias name ABC vsan 30
 member pwwn

- Verification: sh fcalias

- Creating zone and Zoneset using ALIAS:

 zone name ABC vsan 30
 member fcalias DISK1
 member fcalias DISK2
 member fcalias DISK3
 member fcalias SERVER

 zoneset name XYZ vsan 30
 member ABC

zoneset activate name XYZ vsan 30


Basic Vs Enhanced Zoning

- By default the full zoneset is local and the active zoneset is fabric-wide

- Order of operations errors can corrupt the Active Zoneset

- Enchanced zoning prevents this by Locking the fabric which ensures people don't 

   accidentally overwrite each other

- Enhanced Zoning works on per VSAN basis

- The lock on zone is released by "committing" the zoneset

- But if Admin forgets to commit, someone else can release lock as well with 

   "clear zone lock vsan "

- Enabling Enhanced Zoning

> zone mode enhanced vsan < Per VSAN Basis

> system default zone mode enhanced < For Entire System

- Configuring Enhanced Zoning doesn't change anything for regular FCALIAS and
   they still remain local by default

- To solve this problem solution is "Device Aliases"

- Device Aliases serves the same purpose as FC Aliases by binding PWWNs to a user 

   friendly name but the difference 

 is that the binding is advertised to the fabric and doesn't remain local only

- Configured as device-alias database

- Changing the zoning mode from normal to enhanced is not disruptive

- Device aliases are advertised through CFS so should not be used in multi vendor environment

+ Configured as "device-alias database"

+ device-alias commit


device-alias database
 device-alias name ABC_Server pwwn
 device-alias name XYZ_Disk1 pwwn
 device-alias name XYZ_Disk2 pwwn
 device-alias name XYZ_Disk3 pwwn
 device-alias commit

show device-alias database

zone name ABC vsan
 member device-alias ABC_Server
 member device-alias XYZ_Disk1
 member device-alias XYZ_Disk2

zoneset name XYZ vsan
 member ABC

zoneset activate name XYZ vsan

sh zoneset pending

zone commit vsan

sh zone active

"sh port-resource module " shows port grouping on MDS 

  (shared vs dedicaed mode), in 5k all ports are in dedicated mode by default.

Deepak Arora


tiritiuk said...

Good article. Just one simple question. Can you enable Enhanced Zoning and use fcalias instead of device alias? I´d like to enable enhanced zoning, but stick to fcalias. Thx

Deepak Arora said...

Using Device Alias is not a Hard Requirement per say but it gives you flexibility that Device Alias propagates through Entire Fabric. On the flip side FC ALIAS always remains local.

Nicolas Michel said...

fcalias can be distributed using the zoneset distribute full vsan X command

But it propagates only to the appropriate VSAN. Device alias use CFS to propagate throughout the fabric.

I would pick a switch, performs all my Device-Alias to WWpN mappings and commit to allow all my Device alias to be propagated.

Then zoning will be easier :)

My 2 cts :)

Anonymous said...

Rule of Thumb :

- Use fcalias in a Multi-Vendor environment.

- Use Device alias in Cisco only environment since Device Alias is Cisco Propitiatory feature.

Also, remember that Device Alias uses Cisco Fabric Services (CFS) to propagate Device Aliases and distributes them through out fabric irrespective of VSAN they belong to. This might not be desirable in specific cases.

Hope this helps.

Best Regards,