One of the great benefits of Storage Area Networks (SANs) is that they are easy to modify and scale to keep pace with your changing business requirements. However, it's critical to follow detailed control procedures, so you can track what has been changed, when, and by whom. That way, if follow-on problems arise from the change, the problem can more easily be traced to a specific change. Once you've verified that your changes have been implemented successfully, remember to update your documentation and capture a new logical and physical SAN diagram to serve as a new baseline.
Replacing and Adding Storage Devices
One of the most common upgrades you'll make is the addition of new devices and the replacement of old ones to increase storage capacity. Carefully consider the placement of new devices to maximize performance and redundancy. To maximize performance, you might consider connecting a host and the storage it accesses to the same switch. For high redundancy, it is a best practice to ensure the device is dual-attached. You'll also want to consider future scalability, ensuring you'll have adequate ports for Inter-Switch Links (ISLs) and storage devices to accommodate future growth.
Adding a new device should have minimal impact on any active traffic, as SANs provide multiple paths to any single destination. Once you've added the new device, compare your new logical and physical SAN diagram to your baseline diagram to verify the correct numbers of devices are visible, and make a new baseline diagram for future reference.
Upgrading and Modifying Your Fabric
Occasionally you may need to upgrade or modify your fabric to add new functionality, or to be consistent with changes in your storage infrastructure. To add new functionality or features, you may need to turn on a license key or download and install new switch firmware. If your SAN has built-in redundancy and rerouting, these procedures can usually be performed without disruption.
Expanding a Fabric
You may expand your fabric by adding a switch, replacing a switch, or by merging multiple fabrics into one. Because switches are designed to cascade automatically into an existing fabric, adding or replacing a switch in an existing fabric is relatively straightforward. A replacement switch should be configured to match the one it is replacing. Make an effort to maximize fabric performance and availability, and consider various fabric configurations including zoning, switch parameters, and licensing. Fabric scalability manuals and documentation will assist by outlining the necessary procedures.
Extra planning is required when merging multiple fabrics into one (joining SAN islands), since multiple environments will be affected. Again, fabric scalability manuals and documentation will assist you and help simplify this process.
 Previous: Secure Your SAN
 Next: Prepare for Storage Area Management
|
Subscribe for Nth News & Events
Email this page to a friend