When using multi-instance failover clustering (used to be called active-active) in SQL Server 2005 and 2008, I'd like to know what you configure the min and max server memory to.
For a two-node multi-instance cluster (with two instances, one on each node), the best-practice is to configure min server memory to 40-45% on each instance so that when the failover occurs the two instances don't end up with radically unbalanced amounts of memory, because the new instance may apply undue memory pressure to the already-running instance.
Although this is a best practice, I'd like to hear from people who have this situation - what do you configure the memory settings for the various instances? Do you make them equal or do you prioritize by the workload running on each instance? Do you make use of WSRM? Do you dynamically alter the memory settings based on post-failover cluster configuration?
PS I don't need info on how memory management works, or why the best practices exist - I know all that - I'm interested in what people are doing for real.
PPS Note, I'm not interested in SQL 2000 - it's memory manager didn't respond to that kind of memory pressure so best practice was to set max server memory to 50% each instance. Yuk.