I am extending layer 2 between two datacenters for server clustering. 4 servers in total, 2 in each datacenters. only one group is active at any time. in the diagram, i have 4 switches connected via layer 2 trunk. thay are cat 3560's.

questions?

my plan is to put all switches in same hsrp group, only dc1-sw-01 will be the active and dc1-sw-02 standby and both dc2-sw-01/02 will just be listening to take over if both dc1-sw-01/02 went down. can someone suggest something better?

With regards to spanning-tree, dc1-sw-01 will be the root and dc1-sw-01 secondary and make dc2-sw-01/02 secondary as well for the vlans. any better ideas?

dc1-sw-01/02 should be the active switches in the topology until failover to datacenter happens.

Also has anyone done this before - please share you design.

Thanks in advance for any advice.

Francisco