SAN Considerations (4047314)

The following information has been extracted from the NetVault: Backup Administration Guide; This very important SAN configuration information is often overlooked when configuring devices within a SAN so it has been placed in the Knowledge Base to ensure that this consideration is noted.

For more information on this topic, please see the Administration Module 1 Introduction to NetVault Backup-Web-based Training

• In a SAN environment, you must use persistent binding (also known as SCSI mapping, persistent reservation, or persistent naming). NetVault Backup cannot communicate with a library if its logical address changes as a result of changes within the SAN. Persistent binding assigns a fixed logical address to the device, which does not change as devices are added or removed within the SAN. For the Fibre Channel Host Bus Adapters (HBAs), you can map the Fibre Channel device address (World Wide Name (WWN) or World Wide Identifier (WWID)) or Loop ID to the logical SCSI address. This ensures that changes within the SAN have no impact on the NetVault Backup operations.
• You must also use persistent binding when the server and fibre devices are attached to separate switches or when zoning is implemented. NetVault Backup does not support multipathing to a tape library or device, so only one channel should be logically or physically configured for use to ensure consistent communication path.
• You should not use the tape libraries or drives on the same switch or in the same zone that has disk devices attached. Problems might be encountered if packets from both device types co-exist in a SAN environment. Therefore, you should use separate HBAs for these devices.
• Apple supports multipathing in FC Host Adapter and XserveRAID, and often this is the default setting after installation. However, multipathing is not supported in NetVault Backup. Therefore, the connections should be logically or physically separated to ensure a consistent communication path.