Active/Active Exchange 2000

[Ayman Altounji]

Hi. I've got the Compaq Cluster Training and it say's that active/active is possible with Exchange 2000 on the CL380 but it doesn't go into detail. How? Is there any way for each node to own it's own physical drive? I have two controllers. And, I did try setting the controllers to active/active, configuring one mirror set as one logical drive on host port 0 and a seperate mirror set as a logical drive on host port 1 (and a third mirror as my quorum on port 0) but the cluster never saw the second drive as a resource. Am I missing something?

Also, the book says to put the binaries on the shared drive while MS says to put them on each nodes C: drive. Again, the book doesn't go into detail on why. Why is that?

TIA,
Chris

[Ayman Altounji]

Also, I'm now noticing that occasionally my shared physical drive does not come online. The current setup has my quorum on one pair of mirrored drives, ID 2, controller 1, LUN 1, host port 0. This drive shows up in 2000 as logical drive q:\, Disk 0, Online and is configured as a basic disk. My other logical drive used for shared storage is 4 36gig drives in a raid 5, ID 2, LUN 2, controller 1, host port 0. In Windows 2000 the drive shows up as drive z:\, Disk 1, Online and configured as a basic disk.

The problem is that after a failover I can't see z:\ or q:\ in windows explorer. Windows 2000 Disk Management tells me that these drives are there, healthy, and online. The shares that are on these drives are available. But, the physical drives themselves are not accessible (error: z:\ is not accessible. The folder was moved or removed) from the machine which claims to own them, which means that any application (Compaq Veritas EBS) which installs itself on the physical mapping of the shared storage is now unavailable. The physical drive shows up in Cluster Manager as online. And, exchange 2000 still works.

Any ideas?

[Ayman Altounji]

Here are some answers regarding Exchange. We'll get back with you on the other questions as soon as we can.....

Q: Also, the book says to put the binaries on the shared drive while MS says to put them on each nodes C: drive. Again, the book doesn't go into detail on why. Why is that?
A: This question seems to deal with a difference between Exchange 5.5 and Exchange 2000. With Exchange 5.5 the application binaries are installed on the shared drives and with Exchange 2000, they are installed on the local drives. This comes from the differences between the clustering solutions. With Exchange 5.5, the solution is simply a failover solution and can only accommodate one instance running in a cluster. Exchange 2000 has dedicated cluster resources and only requires instance information on the shared drives, thus the ability to do active/active configurations.

Q: I've got the Compaq Cluster Training and it say's that active/active is possible with Exchange 2000 on the CL380 but it doesn't go into detail. How?
A: It is possible to have an active/active cluster configuration on the CL380. To do this, install Exchange 2000 on both nodes in the cluster. Second, create a virtual server that Exchange will use (i.e. a group with at least one disk resource, IP address, and network name). Lastly add a ?Microsoft Exchange System Attendant? Resource to the cluster group. By adding this resource, all of the required databases, log files, and directories are created on the disk in the virtual server. This is only possible with Exchange 2000, not 5.5.

Important note: Active/active Exchange configurations are not recommended by Microsoft. This is because of virtual memory fragmentation that occurs during the Exchange server operation. After a failover, it can not be guaranteed that each of the users can be reconnected to the Exchange server.