Zoning Best Practices

[mugurs]

@Richard
We have some latency spikes on our V800 and they found that one of our hosts is overprovissioning the array.
The plan of action starts as follows:
"Host balance is wrong, hosts should be in different node-pairs. This is mandatory and stated in the 3PAR best practices. HOSTS should not be in the same node-pair but in different node-pairs.
A change in the host zone configuration is needed".
Maybe I understood the other way around. I think the way I should understand this is "try to zone that specific host not to only one pair of nodes but to the other pair of nodes as well" as we do have 2 pair of nodes but that specific host is zoned only to ports from 1 pair of nodes.

thanks,
mugurs

[ailean]

Sounds like bad wording, maybe implying all the hosts are only on one node pair and should be split so similar numbers of hosts on each node pair or that the load isn't even between pairs and some busy hosts need moving to the other node pair.
Very busy hosts can be zoned to all four nodes but it'll still reply on the host/application being able to evenly balance it's IO across all active paths.

[Josh26]

@Richard
"Host balance is wrong, hosts should be in different node-pairs. This is mandatory and stated in the 3PAR best practices.

I recommend asking where this best practice guide is available. With similar statements I often get the answer "it's not for public release", which gives you a good way to explain why you didn't follow the process.

[Richard Siemers]

"Host balance is wrong, hosts should be in different node-pairs. This is mandatory and stated in the 3PAR best practices. HOSTS should not be in the same node-pair but in different node-pairs.
A change in the host zone configuration is needed".

The wording is funky indeed, but I believe the intended meaning is that you need to rezone the hosts to use both node pairs. Especially under the context of what you have provided about your current zoning. The part that says "HOSTS should not be in the same node-pair" is referring the context of your 4 node system, where you have hosts only connected to a single node pair. I believe the true intent of the author is that "HOSTS should not just be connected to 1 node pair, but to both node pairs"