Good article. Covered the basic configurations that people are "thinking about". Thanks.

I've set up multi-node Oracle RAC that uses a private interconnect for very quick block movement needed to keep the nodes consistent. This limits the distance nodes can be from one-another. (side note: I wonder how fast the interconnect really needs to be since once we accidently had the private traffic going over the slower public network for a time and it worked ok.).

So my SQL Server questions have to do with the new feature of separated disk.

To keep the nodes consistent...is it simply relying on mirror like transaction shipping from DB to DB? Are there issues with speed if non-shared disk instances are far away?

Secondly, it sounds like the replicas with separate disk have to be read-only at best....like mirroring? is that true?

Also, the AO is described as a collection of DBs, not instances....or do I have that wrong? That would make it on a par with mirroring.....mirroring doesn't deal with the system DBs and all they contain (authentication, sql agent stuff, etc.. etc...). Does AO deal with replicating system DBs to instances using separate disks?

My biggest desire is to have something that looks like a cluster (with all its failover wonderfulness) across a long distance with separate disk. I don't mean something that does it halfway like mirroring on a database level....I want the whole instance to be replicated including system dbs. I don't want to script off pieces of the sql server instance and restore them to really get the failover up to speed....like logins and agent jobs and other stuff that changes over time.

I dont need the failover to be updatable....just to be "complete".

P.S. I have read about partial isolation for DB users and its only a halfway fix for that particular issue.

comments please, thanks.