VA 7400 - NT Cluster (difficult)

[Copis]

Hello All,

I'm planning to migrate my NT-cluster that is now running on a Compaq RA4000 to my new HP VA7400. I proceeded by installing a second HBA in both my cluster nodes to connect them to the VA7400. This works fine, both the nodes see the LUN's from the VA7400 and both the nodes see the ntfs partitions in explorer I created. BUT, when I want to add a "physical disk" resource into "cluster administrator" there are no drives found. The cluster only sees the Compaq disk array as cluster-possible disk and NOT the HP's. Is it possible to add the HP VA7400 as a "shared SCSI" device for the cluster ?

Thanks in advance.

[Erwin Zoer_1]

Hello,


It is definitely possible to add logical drives on the VA7400 discovered and accessible under Windows NT as physical disk resources in a cluster. I have done so myself in the past.

Based on the information you have provided, I suspect the problem is within the current configuration of the logical drives within NT.

Since you are able to access the NTFS partitions created on all LUNs from both cluster nodes, this indicates that there is no hardware problem underlying the problem of not being able to add the VA's logical volumes as physical disks in the cluster.

First of all it is very important that the LUN's you have created have been assigned the same drive letters on both cluster nodes. It's important to verify this using FTEdit. Run it on both machines and make sure that the same disk signatures have been assigned the same drive letter. If this has not been the case, correct the problem using disk administrator and reboot both cluster nodes to be sure. Next attempt to add the physical disk resources.

Should this not apply or fail. It would be important to check the following registry keys on both cluster nodes:

HKLM\System\CurrentControlSet\Services\ClusDisk\Parameters\AvailableDisks

Before disks can be added as physical disk resources into the cluster configuration, this key must list the respective disk signatures. If there are no signatures, you will not be able to add physical disk resources. In this case progress to the next step.

Using the NT server resource kit's utility FTEdit.EXE find out which disk signatures are associated with the drive letters you have assigned to the VA's logical volumes. Check if any of these signatures is listed under:

HKLM\System\CurrentControlSet\Services\ClusDisk\Parameters\Signatures

on both cluster nodes. If signatures are listed there, these disks cannot be added into the cluster configuration as physical disks because the cluster service believes these disks have already been configured into the cluster configuration. Remove the signatures on both nodes, if any, from this key and restart your cluster nodes. After the reboot attempt to add the physical disk resources again.

I hope this helps.


Best regards,


Erwin

[Copis]

Dear Eric,

I think we're on the right track here,

When I check the Available disks key I see new disks signatures and they are not in the signatures key (so they should be available to the cluster).
When I check closer I see that all the signatures in the registry under "available disks" are different in both registries on both nodes. Shouldn't these signatues be the same? I guess so because if I look in the signatures key I see the signatures of my existing disks and they are the same in both registries. But why are they not ??? What's the proper procedure to add a partition and to have both nodes use the same signature without putting one of their own? When I create a LUN and start disk admin on node 1 it needs to write a signature to the disk. After creating and formating the partition I start the disk admin on node 2. This node also asks to write a signature.
Can I maybe manually put the signature into the registry (danger)?

Any idea...

[Enes Dizdarevic · Accepted solution]

When you want to add additional shared disk in MS cluster first phase (writing signature and assigning drive letter) must be done without cluster services and cluster disk driver loaded. If you tried to write signature on disk while both servers and cluster service are running second node will not be able to access signature and will try to write signature again. For proper procedure you can read http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q175278&LN=EN-US&SD=tech&FR=0&qry=cluster%20shared%20disk&rnk=3&src=DHCS_MSPSS_tech_SRCH&SPR=WIN2000