VSS Migration from Dual to Quad Sup720

[Benjamin Story]

We have an existing VSS pair (6509-E) that has always had the traditional dual supervisor engine deployment.  We have two additional supervisor engines and now have the proper code revision to support quad supervisor engines.  What I'm concerned about is that the new supervisor engines were once in production and still have data on nvram:.  I've put the proper code revision onto the new supervisor engine's disk0:.  When I boot the new image from rommon, will it download the current configuration from the active supervisor engine automatically and just ignore nvram:?

[Viral Bhutta · Accepted solution]

Hi Benjamin,

Please refer to below doucmentation from confgiuraion guide as well as whitepaper on VSS.

Basically it will synchronize all the parameters which are required so you should not worry about the nvram. You just need to make sure that you boot fromt the same software imagen as in acitve (SXI4 or later)..

"When you use VSS quad-supervisor uplink forwarding, the in-chassis standby (ICS) supervisor engine acts as a DFC line card. Only one processor, the SP processor, acts as the DFC line card; the RP processor is reset to ROMMON. During the bootup, once the chassis level role is resolved, the ICS downloads the image from the in-chassis active (ICA) supervisor engine. Once the supervisor engine is booted with the image, it will function in the same way as a DFC line card. All applications running in virtual switch (VS) view the in-chassis standby as a DFC line card."

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/vss.html#wp1204229

"In addition to fully booting the in-chassis standby supervisor and providing fully operational uplink ports, the RPRWarm redundancy mode also provides synchronization of the necessary information to allow the In -chassis Standby

supervisor to reload and take over as the in-chassis active supervisor if needed. The RPR- Warm redundancy mode

synchronizes the following key variables and data structures:

● Startup-config

● Vlan.dat

● BOOT ROMMON variable

● CONFIG_FILE ROMMON variable

● BOOTLDR ROMMON variable

● DIAG ROMMON variable

● SWITCH_NUMBER ROMMON variable

"

https://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps9336/white_paper_c11_429338.pdf (page 34)

Hope This helps

[Benjamin Story]

Thanks for the help.  I installed the sup720s this morning and everything worked well.