Re: RAC , Sun Cluster and EMC disks

"Amit Ghosh" <aghosh6_at_attbi.com> wrote in message news:<nG7M8.133311$ux5.182296_at_rwcrnsc51.ops.asp.att.net>...
> I am interested in setting up a RAC ( Real Application Clusters) environment
> using SUN hardware and EMC disk subsystems.
>
> Some issues
>
> 1) Is using Sun machines with EMC disks certified for RAC ? I do understand
> fromm Metalink that Oracle corp. only certifies only software required but
> the hardware is certified by the vendors. It would seem that sun should
> certify the usage of EMC with their systems but there probably is a conflict
> of interest here. Is anyone using RAC on SUN systems with EMC disks ?
>
> 2) We would like to use 3 nodes in the cluster. Again metalink says that
> only two nodes are supported RAC/Sun Cluster 3.0 environment. However there
> is a caveat in the following explanation given :
>
> "Sun Cluster 3.0 supports up to eight cluster nodes. Sun plan to extend this
> to 64 nodes eventually. Sun Cluster v2.2 had a previous limit of four nodes.
> Real Application Clusters (RAC) is supported with Solaris 8 (v2.8) and Sun
> Cluster 3.0, though only two nodes are supported at this current stage. The
> limitation on SC 3.0/RAC is due to the implementation of SCSI 3 Persistent
> Group Reservation PGR in the storage subsystem. SC 3.0 uses PGR for quorum
> management for more than 2 nodes. SCSI 2 Reserve is used by SC 2.2 and 3.0
> for 2 node clusters. SC 2.2 uses a terminal concentrator for greater than 2
> nodes. Sun will support PGR in T3 storage in an update but Sun will not
> support PGR in earlier storage offerings (e.g., photons - A5200). EMC,
> however, does supports PGR and these third-party vendors are now responsible
> for certification against Sun Cluster. Sun Cluster 3.0 RAC support will be
> certified to 4 nodes when the T3 storage upgrade is released. Certification
> to 8 nodes will happen at a later date"
>
> The key line here is "EMC, however, does supports PGR and these third-party
> vendors are now responsible for certification against Sun Cluster". Does
> this mean then that we might be able to use a 3 node cluster when using EMC
> disks.?
>
> Any insights or experiences would be appreciated.
>
> Amit

Hi Amit,

AFAIK the limitation is because of a hardware limit of the sun storage. This hardware limit was solved I think in the last weeks. Currently they are able to support 4 node clusters. To use EMC and Sun in the same cluster you have to get some form of confirmation from sun that they support this configuration. There are customer's which are running with that configuration.

Regards
Steve Received on Fri Jun 07 2002 - 21:40:01 CDT