Right now I am working on giving a client a recommended version of firmware for their Cisco MDS Fibre Channel switches. For FICON, the recommendations are easy, but for Open Systems there are so many choices. So what am I going to recommend?
FICON Switches and Directors
For FICON switches, sticking to the FICON (IBM Mainframe Fibre Connection) recommended versions (which are determined by the IBM System z Mainframe team), is a very good strategy. The best place to get these is here (standard IBM logon is required). Just look along the right hand column for the release letters.
The SAN-OS and NX-OS release notes found on the Cisco website also show recommended versions for FICON. For instance have at the look at the FICON recommendations table in the releases notes for version 5.2.2a that you can find here. The upgrade path is just below the table I have linked to. This link will get outdated over time (as newer versions come out), but you can list all the release notes here.
If you are using a IBM TS7700 you should also be aware of this page on the IBM Techdocs site.
So based on current versions, if you are running SAN-OS 3.3.1c or below you need to move to 4.2.7b (as per the non-disruptive upgrade path). I strongly recommend you get to at least version 4.2.7b and start planning to move to release 5.2.2 (provided your hardware supports it).
For open systems attached Fibre Channel switches there are a number of versions to choose from. There are five things to consider:
- Being on the very latest version has a small potential risk (of un-discovered bugs). However being on very old versions has a greater implicit risk (of being exposed to KNOWN bugs). Just because you have not hit a bug yet, does not insure you from potential issues, especially if your SAN is growing.
- Your hardware. Some older Generation hardware is not supported at higher levels (for example Supervisor-1 cards cannot go past SAN-OS 3.3.5b) but later generation hardware is not supported at lower levels (for example Fabric 3 modules need NX-OS 5.2.2). The Cisco recommended versions page is the best place to confirm this.
- End of life. As SAN-OS reached end of development in 2011, 3.3.5b is the best choice for all hardware that cannot upgrade to NX-OS. However be aware that some Cisco Generation 1 hardware (such as 2 Gbps capable hardware) will go end of service in September 2012 (for example Supervisor-1 cards and MDS 9120 switches). Links for this are below. Of course your service provider may choose to offer support beyond the Cisco end of life date, but instead of updating code, maybe you should be updating hardware.
- You need to also upgrade your Fabric Manager to at least the same or a higher version than your switches are running. One important thing to be aware of is that from version 5.2, Cisco Fabric Manager has been merged into a new product called Cisco Data Center Network Manager (DCNM).
- You need to be on at least NX-OS 4.2.7 or 5.04 because these releases introduce the slow drain and congestion detection feature. This is a must have for every busy SAN.
So what this mean is that for open systems as at April 2012, I recommend you install 3.3.5b for Gen1 hardware, 4.2.7e for Gen2 and Gen3 and 5.2.2a for Gen4 hardware.
For more details on when things are going end of life, check the following websites:
End-of-Sale and End-of-Life for the Cisco MDS 9000 SAN-OS Software Release 3.x
Cisco MDS Director Modules End-of-Life and End-of-Sale Notices
Cisco MDS 9100 End of Life and End of Sale Notices
Cisco MDS 9200 End of Life and End of Sale Notices
Finally it is well worth bookmarking the following links to help you with any updates (the middle links needs a Cisco CCO login):
Cisco Release Notes
Cisco MDS 9000 NX-OS 4.2(x) and SAN-OS 3.3(x) Upgrade and Downgrade Guide
Cisco NX-OS Release 5.0(1a) and SAN-OS 3.3(x) Upgrade and Downgrade Guide
Cisco NX-OS Release 5.2 Upgrade and Downgrade Guide
And thanks to Glen Routley and Filiph Westman for proof reading this post.