VSAN-Default

[K P SIM]

Hi, Cisco Gurus:

I need you guys to answer the following burining questions of mine:

Q1.

I have seen many UCS implementations being done by Cisco partners with VSAN 1, the default VSAN, due to its easiness and pre-configured to be active in both fabrics A & B.

I know it is not recommended as per Cisco's best practice, but I know to know the LIMITATIONS or CONS of using Default VSAN 1,

1- Un-isololated as it is a single vlan found in both fabrics, AM I right?

-Or it is OK

2-Single Point Of Failure

3-Any others as I would really like to know so that we are on the same page and others will learn from our discussions here, etc.

Thanks.

SiM

[Tushir_Pruthi]

Hi SIM

For SAN connectivity UCS is generally connected to Cisco MDS switches. VSAN is unique feature of Cisco MDS switches. Brocade switches do not support VSAN.

VSAN 1 is predefined VSAN on any MDS switch by the vendor. By default  VSAN 1 owns all the FC ports on the MDS switch. VSAN 1 cannot be deleted as well.

Normally Storage Administrator creates new VSAN's and move respective FC ports to new VSAN's from VSAN 1.

Multiple VSAN's are created sometimes as switch is shared among multiple customers (from service provide vew point).

And in some case Administrators create multiple VSAN's for dividing SAN between production and development.

Thats the reason we need to tag same VSAN number to the UCS Blade service profile.

As we do not use VSAN 1 on MDS switch, so we also do not use VSAN 1 on UCS also.

Thanks,

Tushir Pruthi

[gerlee]

Good stuff. I'd be interested in hearing more about the Cons/Limitations.  For example, I have a customer who has "gotten it to work" by using VSAN1 everywhere, but I can see it will be required to have deeper detail for why not to do that.  I think SIM's on the right path in thinking, would like to hear more from the community.

Thanks,

-Gerald

[Tom MacDonald]

Working in secure environments, I would never use VSAN1. Some like to seperate traffic with different VSANs and/or apply some QoS policies to a specific VSAN perhaps.

The "easiest way" IMHO is probably for the less experienced or lazy....

Mike