MDS Switch Redundancy

[mynetwork014]

Hi,

I have two CISCO MDS 9148 switches, Now i want to make it as redundant switches. For that configured with below settings

on SW01:

created vsan(300), Assign the interface fc1/1 to vsan.

created zone(serverzone), added pwwn number of server1_controller1  and activated zoneset(serverzoneset)

interface fc1/3 (directly connected to SW02)
switchport trunk allowed vsan 1
switchport trunk allowed vsan add 300
no shutdown

on SW02:

created vsan(300), Assign the interface fc1/1 to vsan.

created zone, added pwwn number of server1_controller2  and activated zoneset

interface fc1/3
switchport trunk allowed vsan 1
switchport trunk allowed vsan add 300
no shutdown

But when i am doing testing with two scenarios the result confused me:

1. disabling SW01 interface fc1/1, server1 not reachable to other servers (in same vsan)

2. disabling SW02 interface fc1/1, server1 reachable to other servers (in same vsan)

So i believe switches not workig as redundant, so any special configuration required for redundancy ?

Thanks in advance... 

[Walter Dey]

You can only have one active zoneset per vsan; if you have separate zoneset on each MDS and activate them on either switch, you just overwrite them.

If your ISL is up, just create the 2 zones, add them to the zoneset, and activate this zoneset.

To avoid this trouble, configure enhanced zoning:

Cisco SAN switches have three zoning modes which dictate the behavior of zoneset distribution within the fabric. These modes are:

1. a) Enhanced Zoning: This method is the recommended for all Cisco native VSANs. In this method full zone database synchronization (full distribution) is enforced. Bulk zone information transfer is optimized such that zone-merge, and large activations happen more efficiently. Single administrator change locking is enforced.  Before another administrator can make changes, any pending changes must first be completed and activated.
2. b) Basic Zoning with full zoneset distribution: This method is recommended only if Cisco Enhanced Zoning cannot be used (interop VSANs). Upon any zone activation, the full zone database of both active and inactive zone information is pushed out and synchronized fabric-wide. Multiple administrators managing from different switches can overwrite each other’s changes (i.e no Locking).
3. c) Basic zoning with active-only zoneset distribution: This mode is not recommended for production Cisco SANs. In this method an independent zone database is maintained on each switch in the fabric. The ACTIVE zones and zoneset are in sync across the merged fabric. Inactive zones and zonesets are NOT necessarily in synchronization fabric-wide and can be difficult for SAN administrators to manage. Multiple administrators managing from different switches can overwrite each other’s changes (No Locking).

To enable enhanced zoning via CLI follow the following procedure.

Switch# conf t

Switch(config)# zone mode enhanced vsan <vsan number>

Switch(config)# end

Switch# copy run start

To display the zoning mode status

Switch# show zone status vsan <vsan number>

https://supportforums.cisco.com/document/109756/configuring-and-troubleshooting-mds-enhanced-zoning

[Walter Dey]

Btw. I don't understand why you are doing this; in FC SAN, it is best practise to have 2 isolated fabrics (in your case 2 MDS, no ISL in between); and servers and storage are dual homed. If a SAN (one MDS in your case) will fail, multipathing on the host will handle that. Therefore HA is done on the server resp. storage. Each fabric has their own vsan, and therefore active zoneset and zones.

[mynetwork014]

Thanks Walter,

First of all, In two switches all configuration is same except pwwn numbers.

You mean no need to connect two switches physically (interface fc1/3 and no trunking) ?

Then How HA will work ? 

[Walter Dey]

Hi

Yes, no ISL between the 2 MDS ! If you want HA, you need director class MDS, with 2 Supervisors.

Walter.