Hi Walter
Thanks for the answers.
I can't really see any features or configuration limits that would disqualify running FI's in switch mode when using either a direct attaching storage system or separate front end ports on larger storage systems (VMAX / UCP). But I would love to hear otherwise :-)
Sure the numbers of VSANs, zones, FLOGI's, buffer credits are not impressive compared to the smallest MDS models but when having maximum 160 server it wouldn't be a problem. Having the shortest and most predictable path to storage and simple setup is a big plus in my eyes.
Have seen a lot of cases, especially now with all-flash, where customers has a mix of other/older servers attached to FC switches where different port speeds cause loss of buffer credits - creating back pressure. And the lack of standard for FC port-channels cause link congestions between FI's and Brocade switches and being hard to troubleshoot because of microburst congestion not being caught by monitoring tools.
Zoning have never been the most loved task for storage(/server) people so having UCSM take care os this makes day2day operations a lot easier to perform and troubleshoot.
If connectivity to other equipment or site is needed then separate VSANs pinned to other uplinks can be used, again to separate traffic and make performance predictable.
The dual FI reboot when changing from end host mode to switch mode and the other way around was fixed in 3.1(2b), check CSCuy20188.
It is now also possible to create and exchange based load-balanced port-channel between UCS FI and Brocade. Does require a Brocade Director switch with the new FCoE linecard though.
