I have a cluster A/P 4 processor 4 gig of ram with 3 gig allocated to SQL
server. I have put on the same cluster my testing of 2005 and will switch
over soon.

How does SQL Server deal with RAM between the 2 instances?

TIA

__Stephen

Howdy,

The two SQL Server engines won't know about each other's memory usage. So
you have to set things up accordingly to ensure your main SQL Server engine
isn't going to get starved by your 2005 test instance.

Also, if you've installed the two separate engines, like it sounds you have,
then what you can do as long as you're running the engines in separate
cluster groups, is run each engine on a separate node of the cluster. That
way one isn't going to fight the other for memory or CPU.

The gotcha with this is if you have a fail over you need to ensure that each
instance of memory is going to have enough memory to start properly. So with
4GB of RAM available, you want to say set your production instance to use a
max of 2.8GB and your 2005 test instance to use a max of around 1GB.
Otherwise there is a risk that whichever instance fails over may not start
properly if it can't grab the amount of memory you've allocated to it.

Hope that helps!


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