Multiple SAN Uplinks

[amit.bhagat]

Hi Guys,

Just wondering if UCS supports multiple SAN uplinks to different physical SANs (similar to Disjoint L2 in LAN)?

Regards,

Amit.

[Manuel Velasco]

Hi Amit,

Yes you current configuration will work with UCS, the only thing you have to know every vhba can only be pinned to a single uplink interface which means a single vhba won't be able to talk to both SAN arrays, and that you will have to use static pinning to make sure you assigned each vhba to the correct SAN array.  

If you want to have the a single hba have access to both SAN arrays, I would recommend you to connect both SAN arrays to the same SAN switch and make the correct zoning configuration. Take a look at the link below

Designing and Deploying a Cisco Unified Computing System SAN Using Cisco MDS 9000 Family Switches

http://www.cisco.com/c/en/us/products/collateral/storage-networking/mds-9500-series-multilayer-directors/white_paper_c11_586100.html

Please let me know if this helps

[amit.bhagat]

Hi Manvelas,

Thank you for replying and the link.

If I understand correctly, static-pinning will pin the vHBA to the uplink port (or port-channel) but it doesn't modify the "allowed VSANs" on the uplink port. (Atleast, that's what happens to VLANs in LAN). Does it affect operationally, during failure, for example?

I know it can be catastrophic in case of LAN having Disjoint L2 but can be rectified using VLAN Manager or VLAN Group feature. Is a similar feature available for SAN?

Regards,

Amit.

[Walter Dey]

Yes this can be done ! Be aware that most likely the only solution is Fibrechannel End Host Mode (NPV); this restriction applies, if some of your FC fabrics are non Cisco (MDS, N5k);

FC switching mode not possible: no FC interop mode support on UCS FI, connecting e.g. a Brocade fabric,

Regarding implementation: pinning or dedicated VSAN per FC fabric.

I don't know any customer that is using pinning; technically ok, but a management challenge.

Use eg. a pair of VSAN's for fabric 1 and fabric 2

vsan 10 fabric 1 A

vsan 20 fabric 1 B

vsan 30 fabric 2 A

vsan 40 fabric 2 B

On your service profile, you create 4 vhba's and assign them accordingly

vhba0 -> vsan 10

vhba1 -> vsan 20

vhba2 -> vsan 30

vhba3 -> vsan 40

I have many such implementations, it is state of the art.

This has been discussed before, see eg.

https://supportforums.cisco.com/discussion/12042816/ucs-connecting-two-different-storrage-two-different-san-switch