Firstly regarding the 8 LUNS within the Consistency group.  You don't need to have all 8 LUNS in the same consistency group, if these are just separate virtual machines/VMFS datastores. I would just keep a consistency group relevant to the Exchange system you are trying to protect.  (You can have a consistency group per Exchange storage group)  For an Exchange server on a VM, you'll have the following  to protect and replicate:  1)The VMware datastore that holds the bootfile (VMDK) for the Exchange operating system. 2)An Exchange Database  LUN(s) (lets assume 1 database per Exchange storage group) 3)the Exchange Log Lun so as an example you could put the above 3 LUNS into a Consistency group.  Actually I just noticed you said you've an Exchange Cluster so okay I see why you have so many LUNS in the consistency group. I take it they are all related to the Exchange Cluster and Exchange ?  As you are only using MirrorView/A and no scripting or other tools to replicate, then your replica on the other site will be a "Crash Consistent" copy of Exchange.  If you recover (fail over/promote), you may have to run some tasks on the Exchange system you are recovering at the other site in order to get it up and running.  See if the docs below help and let me know.  You can also try a test recovery.  if you have SRM you can use the test option, then have a look at the recoverd vms(s). Or manually you can snapshot the secondary LUNs (of each mirror pair) and mount those snapshots onto the standyby server at the other side, bring up the Exchange system, and have a look. Make sure the network you bring the vms into, within ESX does, not conflict with the actual network for the primary machines as you dont want the test copies you are bringing on-line to interfere with the production Exchange system.   Have a read of :  1)MirrorView Knowledge Book FLARE 29 (in Powerlink) 
Hi guys, I have a client who is using a cx3-10 and are replicating using mirrorview/a They have 8 luns in a single consistency group which are replicating to the DR site. The exchange vm's vmdks placement is, the system vmdk on one lun, logs on a second and DB on a third. I was wondering when you replicate the luns would the consistency group understand the relationship between the exchange DB and logs? If not would it be better to place the logs and DB on the same LUN? If anyone can point to some docs about this, or has any ideas it would be much appreciated. Thanks Dougie
Vmware SRM and consistency groups