Dell Cluster Configuration Support Matrices
- SE500W - The SE500W cluster is a U320 SCSI solution with 2 homogeneous Dell PowerEdge servers, Dell PowerVault 22xS storage enclosures with U320 drives, and Dell PERC 4/DC or PERC 4e/DC RAID controllers in a Microsoft Cluster configuration.
SCSI Cluster Overview
A PowerEdge SCSI Cluster is an integrated system of components, including a pair of PowerEdge servers, up to 4 PowerVault storage systems, a cluster interconnect, and Microsoft's failover cluster software. Microsoft Cluster Server for Windows Server 2003 Enterprise Edition and Windows® 2000 Advanced Server implements a two-node failover cluster that delivers high availability for applications and services. Optional features of a PowerEdge Cluster include Dell OpenManageTM , installation services, consulting services, proof-of-concept testing.
Active/Active and Active/Passive Configurations
Microsoft Cluster Service (MSCS) and all PowerEdge Clusters support both active/active and active/passive cluster configurations. The term active/active refers to a cluster with at least one virtual server running on each node. For example, in a 2-node cluster configuration, when an application is running on Node 1, Node 2 does not need to remain idle waiting for Node 1 to fail. Node 2 can run its own cluster-aware applications (or another instance of the same application) while providing failover capabilities for resources on Node 1. Node 1 in turn can provide failover capabilities for resources on Node 2. An active/active cluster node must be sized appropriately to handle the load of both nodes (in the event of a failover).
The term active/passive refers to failover cluster configurations in which one or more cluster nodes is actively processing requests for cluster applications while at least one cluster node simply waits for an active node to fail. An active/passive configuration is more costly in terms of price/performance because one or more servers sit idle most of the time. It is appropriate for business-critical systems since the applications can use the full power of another server in case of a failure.
PowerEdge S-Series clusters, including the SE400 and SE500, support direct-attach configurations comprising the two cluster server nodes and one to four PowerVault storage systems. In direct-attach configurations, one or two PERC 3/DC RAID controllers (SE400), or one or two PERC 4/DC or PERC 4/eDC RAID controllers (SE500) in each server have cluster-mode enabled. A separate RAID controller can be used for each of the servers' internal drives. A channel from each server's cluster-enabled RAID controller attaches to one side of the PowerVault 22xS SCSI enclosure. These RAID controllers and storage components were designed with clustering in mind. For example, there are enhancements to the following products that allow for SCSI clustering at no additional cost:
- Cluster-mode for the PERC 3/DC (SE400) or PERC 4/DC and PERC 4/eDC (SE500) : Cluster-mode or standard-mode can be enable from the RAID controller's BIOS Configuration Utility
- Cluster Mode for PowerVault 22xS : the Split-Bus Module position switch that allows for both host connections to use all drives. This overrides the factory-default configuration of splitting the enclosure into two separate halves when two host connections are made.
- Auto-Termination for PowerVault 22xS : Some vendor's SCSI cluster configurations require "Y-Cables" to ensure termination of the SCSI bus in the event that one of the servers loses power. The PowerVault EMM modules contain SCSI repeater modules that auto-terminate the SCSI bus in the event that one of the servers fails. This feature allows standard SCSI cables to be used to connect the cluster-enabled RAID controllers to the storage enclosure.
The PowerEdge Cluster SE500 & SE400 use PowerEdge Servers and PowerVault SCSI storage components. These components include the PERC 3/DC, PERC 4/DC, and PERC 4/eDC RAID Controller and PowerVault 22xS storage systems with dual EMM modules installed.
Basic SE500 SCSI Clustering
- RAID Controllers - PERC 4/DC and PERC 4/eDC
- Cluster Storage - Up to 4 PowerVaultTM 22xS SCSI Storage systems with EMM or ZEMM
- Operating System - Microsoft® Windows® Server 2003 Enterprise Edition, Windows 2000 Advanced Server