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New Member

MDS connection problem


I have a problem about Cisco MDS switch connection between servers and interoperability with other Cisco MDS switch.

The topological structure is;

in main (production) site, there exists one Hitachi 9980v storage subsystem which firmware level is 21-14-10 and two Cisco MDS 9506 switches are working together. All servers (file, exchange, database, etc) are attached to these two switches; switches are connecting to each other (cascade)

I had upgraded to Cisco MDS firmware level like Cisco recommendation, first increase firmware level v2.0 (1b) to v2.1 (2b) and then v2.1 (2b) to v3.0 (2a) which I did this operation on December 22nd.

This upgrade done because of some connection problem between servers and storage system. The previous problem was, some servers loosed disks in random times and network to be locked also.

After upgrading the system, it was working fine since December 27th.

Now the problem, nearly all servers loosed to accessing disks.

We were investigated SIM messages and port definitions on storage subsystem but we could not see any abnormal situation.

When we were power off one of these MDS switch, servers were begun to working and switch is still off.

How can I fix the problem?

Kind regards,

Fatih Karakurt

  • Storage Networking
New Member

Re: MDS connection problem

Firstly I would raise a call with Cisco support on this. It hard to determine the problem that is not relatively simple on a forum.

Can you expand your topology a bit, eg. your 9980 is multipathing to your servers through each switch. Are you using HDLM to provide mulipathing between the 9980 and your servers or are you using something else like Veritas DMP? When you say the switches are connected, are you using ISL or EISLs for port channels?

Are all your interfaces on the 9506 showing the WWN of the storage or server? Eg:

show fcns database

Are there link lights on the interfaces that don't seem to be connecting.

Can you do a fcping to the ports on the servers/storage from the switches?

Have you tried the following on the interfaces that are having troubles talk to the server or storage.

sh flogi


debug flogi event interface

There are bound to be a lot more questions but I hope you can get some info to provide on the reason this is happening.

I think it strange that turning off one of the MDS has started the systems seeing the storage again.

I am assuming you are running the ports on the 9980 in point to point mode and nothing has changed over the last few weeks.


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