Upgrading 6807 VSS single SUP

[LennoxConner]

Hello!

I have 3 pairs of 6807 VSS switches. Each stack is single supervisor VS-SUP2T-10G.

Current version is 

(s2t54-ADVIPSERVICESK9-M), Version 15.1(2)SY6

ROM: System Bootstrap, Version 12.2(50r)SYS2

Recommended version is

s2t54-advipservicesk9-mz.SPA.155-1.SY6.bin

It seems like I cannot do ISSU with this upgrade. Is there another way I can do this without a full disruption to our Core network?

If I have to take it out all at once how long will the upgrade take?

Thanks,

[Leo Laohoo]

WARNING: 

DO NOT USE ISSU or FSU/eFSU if upgrading to 15.5(SY) train on a 6807/6880 chassis.  

IMPORTANT:  Read the Release Notes very, very carefully.  

Pay very, very close attention to the "Performing FPGA Upgrade" section.  There are three things everyone must be aware warned of: 

1. You will need console access or line cards will not boot.;
2.  For unknown reason, the line cards needs to have an FPGA upgrade done MANUALLY.  This can only be done once the new IOS gets loaded.  This FPGA upgrade is not "incorporated" in the IOS.
3.  The command to do the FPGA upgrade is a "bug".  For VSS, the command is:

upgrade winters-flash switch <switch-number> slot <slot-number> bundled-image GOLD

For stand-alone, the command is:

upgrade winters-flash slot <slot-number> bundled-image GOLD

See the last option, "GOLD"?  That option is HIDDEN and the fact that it is a hidden option is not documented anywhere else.  
And one final thing, ISSU or FSU/eFSU does not support FGPA Upgrade. 

Use the tried-and-tested method: 

1. Copy the file to the primary unit;
2. Compare and verify the MD5 hash value matches; 
3. Copy the file into the secondary unit; 
4. Compare and verify the MD5 hash value matches; 
5. Change the boot variable string:  Point the first line to the new IOS and second line to the OLD IOS. 
6. Save the config; and
7. Reboot

Once the reboot is complete, there will be some line cards that will "refuse" to boot up.  If a console cable is attached before rebooting the chassis there will be a "large" message stating that FPGA upgrade must be done, however, the command to do the FPGA upgrade is not mentioned.  The time it will take, after the panic has wane, to find the flippin' FPGA upgrade command will obviously run into an hour or two. 

NOTE:  

1. I have been using this method because I have very bad experiences (plural) with ISSU or FSU/eFSU.  ISSU or FSU/eFSU is not a one-size-fits-all.  If it works, ISSU or FSU/eFSU is very useful because it saves a lot of time, however, if it fails then no one can hear you(r) scream when you are driving alone to the site.
2. There are more "rules" about when it is NOT possible to use ISSU or FSU/eFSU. 
3. And, as mentioned above, ISSU or FSU/eFSU do not support FPGA upgrade.