System high availability

A Storwize® V3700 clustered system has several features that can be used to deploy a high-availability storage system with no single point of failure.

For example, for disaster recovery, the Metro Mirror and Global Mirror features can be used to mirror data between systems at different physical locations.

The control enclosure contains a pair of node canisters. If one node canister fails, then the other node canister assumes the I/O and management responsibilities of the failed node canister.

Each Storwize V3700 node canister has redundant host attachment ports. For high availability, use these ports to make at least two independent connections between each host system and each node canister. The system supports the following host attachment options.
  • 1 Gbps iSCSI though canister ports 1 and 2
  • Ports 1 or 2 of the 6 Gbps SAS ports
  • Fibre Channel through 4-port 8 Gbps Fibre Channel host interface adapter
  • 10 GB iSCSI/Fibre Channel over Ethernet (FCoE) (with optional host interface adapter)
    Note: For system where the 10 GB iSCSI/FCoE host interface adapter is preinstalled, the Fibre Channel host interface adapter must be uninstalled from the system.

For example, when you use Fibre Channel SAN-attached hosts, attach the node canisters to at least two SAN fabrics, and attach each host system to both fabrics.

Configure any Fibre Channel host systems to use multipathing software. If a SAN fabric fault or node canister failure occurs, then I/O operations among Fibre Channel host systems and Storwize V3700 node canisters are tried again. Subsystem device driver (SDD) multipathing software is available from IBM®® at no additional charge for use with Storwize V3700. For additional information about subsystem device driver (SDD), go to the Support for IBM Systems website.

Each Storwize V3700 node has four Fibre Channel ports, which can be used to attach the node to multiple SAN fabrics. For high availability, attach the node in a system to at least two fabrics. For high availability, attach the node in a system to at least two fabrics.For high availability, attach the node canister in a system to at least two fabrics. Storwize V3700 machine code incorporates multipathing software to communicate with Storwize V3700 nodes. This software is also used for I/O operations among Storwize V3700 node and storage systems. If a SAN fabric fault disrupts communication or I/O operations, the multipathing software recovers and tries the operation again through an alternative communication path. For high availability, configure your Fibre Channel host systems to use multipathing software. If a SAN fabric fault or node failure occurs, I/O operations among Fibre Channel host systems and Storwize V3700 node are tried again. Subsystem device driver (SDD) multipathing software is available from IBM at no additional charge for use with Storwize V3700. For more information about subsystem device driver (SDD), go to the Support for IBM Systems website and enter the product name in the Product Finder field.

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iSCSI-attached hosts connect to the system through node Ethernet ports. If a node fails, the system fails over the IP addresses to the partner node in the I/O group to maintain access to the volumes.