Best way to provide redundant switching/links to server

We have 3x ESX hosts and 2x SANS that we wish to move to a redundant 10G networking infrastructure.

We have 4x Dell PowerConnect 8024F's to provide our backbone and are configured as so (only core switches relevant to this question):

So the questions are:

1) Do the interconnects between the 4x 8024F's need to be LAG'd or just STP'd

2) As the NICs on the servers are split across 2 switches, does any special configuration need to be done here or on the switches?

3) If a link or switch fails will the switches automatically find a new path to the Server/SAN?

Solution 1:

For the user facing network, STP is fine. Yes, you will have a small interruption as a new tree is computed. However, the convergence time is lower that the TCP timeout so the interruption should be effectively unnoticeable. Only for extremely time sensitive application such as VOIP would you run in to problems, and even those can be mitigated.

For your iSCSI network, you should use multipathing (MPIO). This can detect a failed path much faster and retry before the storage system gives up.