Can 2K5 Cluster can have 2 instances on each node?

Hi,
We have sql 2005 standard installed as cluster on win2k3 cluster with 8
GB memory on each node. We have one virtual sql server named instance on
first node. Can we create one more instance on the same node and
similarly 2 more instances on the second node. The cluster will be in
active\active mode. Our reason for considering this is that we will be
able to fail over one instance from the node 1 to node2 and node2 still
have the 2nd instance running. Is this possible?
Thanks
DeBe
DeBe's Profile: http://www.dbtalk.net/m115
View this thread: http://www.dbtalk.net/t297735
I think you have some misconceptions on how clustering works. The obsolete
naming of "Active/passive/Active..." is partially responsible for that.
Instances are installed to the cluster. You can have up to sixteen
instances on a cluster. SQL Server 2005 Standard Edition supports up to
two-node clusters. Nodes are the host computers for a cluster. An instance
can run on either node, but only on one node at a time. You cannot install
the same SQL instance to two nodes and have them both serviceing data
requests as if they were the same server. SQL Clustering is a failover
technology, not a scale-out technology. You can create two SQL instances on
a SQL 2005 two-node cluster and let one run normally on each node. During a
failure event one node can run both instances, with some performance
compromises of course.
Geoff N. Hiten
Senior Database Administrator
Microsoft SQL Server MVP
"DeBe" <DeBe.25toh0@.no-mx.forums.yourdomain.com.au> wrote in message
news:DeBe.25toh0@.no-mx.forums.yourdomain.com.au...
> Hi,
> We have sql 2005 standard installed as cluster on win2k3 cluster with 8
> GB memory on each node. We have one virtual sql server named instance on
> first node. Can we create one more instance on the same node and
> similarly 2 more instances on the second node. The cluster will be in
> active\active mode. Our reason for considering this is that we will be
> able to fail over one instance from the node 1 to node2 and node2 still
> have the 2nd instance running. Is this possible?
> Thanks
>
> --
> DeBe
> DeBe's Profile: http://www.dbtalk.net/m115
> View this thread: http://www.dbtalk.net/t297735
>
|||I will try to make my problem more clear.
I am talking about 4 different instances and they have 4 different
databases
connecting to 4 very different application.
so
Node1-->InsA-->DBa
Node1-->InsB-->DBb
Node2-->InsC-->DBc
Node2-->InsD-->DBd
So I guess my question is is it possible for just InsA to fail over to
Node 2. So that node 2 is now running with 3 instances and node 1 is
running with 1 instance?
My second question would be about the memory. If out of 8 GB Ram on
each node if 1 GB is assigned to os and 3 GB is assigned to each
instance (assuming 2 instances) and if the third instance from the node
2 fails over how will it get the memory for itself?
Thanks
DeBe
DeBe's Profile: http://www.dbtalk.net/m115
View this thread: http://www.dbtalk.net/t297735
|||You can have up to sixteen instances per cluster. Once the instances are
installed, you can set the preferred node order for each instance. That
determines which node is the normal host for this instance. Each instance
is completely independent from the other instances. You can move each
instance independently between nodes without affecting any other instance.
Just as on a stand-alone system with multiple instances, it is the DBA's
responsibility to make sure there are enough resources for all instances to
function properly. Note that SQL will not rebalance memory amongst multiple
instances. I.E. It will not make one instance give up memory so another one
can have it. You must plan ahead for the situation where one node hosts
more than its normal set of instances.
Geoff N. Hiten
Senior Database Administrator
Microsoft SQL Server MVP
"DeBe" <DeBe.25uu4z@.no-mx.forums.yourdomain.com.au> wrote in message
news:DeBe.25uu4z@.no-mx.forums.yourdomain.com.au...
> I will try to make my problem more clear.
> I am talking about 4 different instances and they have 4 different
> databases
> connecting to 4 very different application.
> so
> Node1-->InsA-->DBa
> Node1-->InsB-->DBb
> Node2-->InsC-->DBc
> Node2-->InsD-->DBd
> So I guess my question is is it possible for just InsA to fail over to
> Node 2. So that node 2 is now running with 3 instances and node 1 is
> running with 1 instance?
> My second question would be about the memory. If out of 8 GB Ram on
> each node if 1 GB is assigned to os and 3 GB is assigned to each
> instance (assuming 2 instances) and if the third instance from the node
> 2 fails over how will it get the memory for itself?
> Thanks
>
> --
> DeBe
> DeBe's Profile: http://www.dbtalk.net/m115
> View this thread: http://www.dbtalk.net/t297735
>
|||Just curious why you need so many instances. One instance can handle 4
DB's.
Tom
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Toronto, ON Canada
..
"DeBe" <DeBe.25uu4z@.no-mx.forums.yourdomain.com.au> wrote in message
news:DeBe.25uu4z@.no-mx.forums.yourdomain.com.au...
I will try to make my problem more clear.
I am talking about 4 different instances and they have 4 different
databases
connecting to 4 very different application.
so
Node1-->InsA-->DBa
Node1-->InsB-->DBb
Node2-->InsC-->DBc
Node2-->InsD-->DBd
So I guess my question is is it possible for just InsA to fail over to
Node 2. So that node 2 is now running with 3 instances and node 1 is
running with 1 instance?
My second question would be about the memory. If out of 8 GB Ram on
each node if 1 GB is assigned to os and 3 GB is assigned to each
instance (assuming 2 instances) and if the third instance from the node
2 fails over how will it get the memory for itself?
Thanks
DeBe
DeBe's Profile: http://www.dbtalk.net/m115
View this thread: http://www.dbtalk.net/t297735