MCX VNX FC host port assignment

Hi all,

In H10938 VNX Unified Best Practices for Performance (see http://www.emc.com/collateral/software/white-papers/h10938-vnx-best-practices-wp.pdf) there is some interesting information on port assignments, however some of the contents lead to questions.

This post is about the FC port assignment best practice.

Quote from the doc:

- First use the even numbered ports on each Front End I/O module before using the odd numbered ports when the number of Front End port assignments are less than the number of CPU Cores.

- Initially skip the first FC and/or iSCSI port of the array if those ports are utilized als MirrorView connections.

In a typical unified enviroment with 2 FC I/O modules per VNX with dual datamovers (let's say a VNX5400) this leads to a rare configuration. Datamovers should be initially connected to port 0 and port 1 on the second FC module. For later expansion of the file-part you can leave ports 2 and 3 unused.

Ports 0 on the first I/O module best practice is to reserve for MV (if used), this makes ports 1,2,3 on the first I/O module available for host-IO. However the best practice is to use the even numbered ports first... That's only port 2...

Because hosts need at least two ports due to redundant fabric concepts this is not a very usable choice.

If the best practice can also be read as "OR use even OR use odd ports first" then this would lead to a best practice that when MV is used ports 1 and 3 are the best choice for host IO.

Anybody can say something about this?

Thanks!