Some SAN solutions use (or can use) 2 subnets. In that case I'd suggest to indeed use a unique vSwitch for each subnet and vmnic. However, for Equallogic I'd recommend to use the Equallogic document on how to set up vSphere5: www.dellstorage.com/.../DownloadAsset.aspx In short: use a single vSwitch with multiple vmnics and isolate each vmkernel to a single vmnic. If you are using a vSphere version older than 5.1, you want to implement the iSCSI/storage heartbeat that the document talks about. If you are using 5.1 this is not needed anymore.
I have setup other vendor's iSCSI with vmware and often their documentation states to use 2 vSwitches with a single NIC in each (if you have 2 NIC's for iSCSI).  This is for iSCSI or NFS (NetApp). Can this be done with Equallogic storage?  Or should I use the single vSwitch method with 2 NIC's in the Equallogic documentation?  Does it really matter since each NIC is bound to different vmkernel with either option? Hardware is.... Dell R620 2 - 10gig NIC's teamed for all network access into Nexus 5548's (Lots of VLAN's for managment, vmotion, vm's) 2 - 10gig NIC's for iSCSI into other Nexus 5548's. All Intel X520-2's (or whatever the name is for that NIC) Also with 5.1 update 1, just to be clear, I don't need the Heartbeat network any more? Thanks!
vmware esxi 5.1 one or two vswitches?