2 fabrics on a switch ?

steve switzer · ‎03-25-2011

Hi

I am new to SANs - done the course years ago and now have to put it into practice.

Problem is -

I have 2 existing fabrics - each with 1 9134 and 1 9124 hosts on the 9124

and storage on the 9134.

Now my designer (who doesnt know SANs ) wants me to connect 2 new 9124s

each with one interface on the 2 existing 9134s in the 2 fabrics above.

When i try attaching them the fabrics disappear or bits of the existing ones appear

in the new fabric,

First - what is the usual practice =

Can i do the above - can i have a number of fabrics on one switch

If i cant - what would be recommended - Just a different VSAN.

The only common vsan on the switches is vsan 1

Thats the default - is the clash causing my problem because i need to get rid of VSan 1

on the new switches

Any info gratefully received - i would like to go away and read this all up but as usual there

is no time for planning - i need to sort this fast

If you need any details let me know

Thanks in advance

Steve

mbinzer · ‎03-26-2011

Hi,

i my mind the goal of having 2 fabrics is to have real redundancy. In other words, the host is connected with one HBA to fabric 1 and with another HBA to fabric 2.

The same on the other end where the storage sits.

This is the typical san configuration that people use today. You are then using some form of multipathing software on the host and storage to deal with the

two path, load sharing, active passive, ect.

In this configuration you can shoutdown one path, i.e. the interfaces on the switches and simply do maintenance ect., upgrade switch software....

If there is a real failure in fabric a you are still running in fabric b and most likely your users are not even noticing.

If you merge the 2 fabrics you are taking this level of redundancy away.

Second abou the failures tha you see when interconnect the two fabrics you are most likely merging the two fabrics and that depends quite a bit on the

existing configurations of your switches.

If you want to do this you may have to talk to TAC first to get sorted out what is configured in one fabric and the other, i.e. if you use the same vsan numbers and have different devices in there you have a problem ect.

thanks...

Matthias