Thanks to all of your help. My original question was:
>I am transitioning a VMS cluster to a Tru64 UNIX 4.0F ASE cluster
>using TruCluster 1.6. The cluster consists of 2 AlphaServer 1000A's
>with a Raid310 box (HSZ20) on a shared SCSI bus. Each 1000A has 1
>RZ1CB (4GB) disk on it's local SCSI bus and the Raid310 box has 5
>RZ1DA (9GB) disks, 4 of which currently form a level 5 raidset with
>the other disk being a hot spare. Now for my problem. From what I
>understand from the TruCluster manual, a shared disk can only be part
>of one TruCluster service, no matter how many partitions it has. Is
>this true? If it is, it looks like I would be limited to one
>TruCluster service with my current disk configuration. Why can't I
>use a separate partition for each service?
The consensus is that you can't use a separate partition for each service
because each service will place the "SCSI reservation bit" on the *disk*
from the system that mounts the disk. Chris Ruhnke added that:
>if you were to set up two services (call 'em "A" and "B")
>and two servers ("Node1" and "Node2"), you could allocate space on device
>/dev/rz1d to service "A" and /dev/rz1f to service "B". When you start
>service "A" on "Node1", the server - Node1 - reserves the disk rz1 to
itself.
>If you then try to start service "B" on "Node2", that server - Node2 -
cannot
>access rz1 because Node1 has it reserved. "DANGER, WILL ROBINSON!"
>You could successfully start both services, "A" and "B", on Node1; but, if
>either one of the services tried to fail over to Node2, the fail over would
>NOT succeed!
Many people suggested that I wait for TruCluster 5.0 because it is more like
VMS clustering in that you can have concurrent access to all of the shared
disks. This won't work for me because 1) I need the system now and am not
willing to field test the software, and 2) TruCluster 5.0 requires a Memory
Connect Interface, which I don't currently have.
Many people also suggested I could solve the problem by partitioning the
shared disk using the capabilities of the HSZ20. This would effectively give
me multiple SCSI disks and allow me to have multiple services, one per
partition. I have decided to do this.
Thanks again for all the suggestions.
-----------------
Douglas Masterson
Boeing Services Company
douglas.h.masterson_at_boeing.com
703-412-6742
Received on Thu Feb 03 2000 - 13:06:27 NZDT