Global namespace: The Future of File System Management, Part 2 - Storage Networking

Computer Technology Review, March, 2003 by Rahul Mehta

Let's replay the scenario with a global namespace solution in place (see Fig. 4):

* A user regularly requests a file that is stored on a server in the NYC data center.

* Today, the NYC server is unavailable.

* Because the user is accessing files through the namespace, he is transparently redirected to the backup filer in New Jersey, and is able to access the file, as if nothing had changed.

Global namespace is the only way to enable immediate, transparent client failover to a backup file server in a different location. When the site failure occurs, client calls to the failed servers are transparently redirected to the replicated servers in New Jersey. No client reconfiguration or network rerouting is required. The time between failure and restored client access to files is minutes, not hours or days.

The benefits of using global namespace to prepare for disaster recovery are significant:

* Disaster recovery is rapid and transparent.

* Little or no user downtime.

* No storage reconfiguration is required to restore client access to data.

* Policy-based failover can be set up and executed without manual intervention.

Conclusion

By now it should be clear that global namespace delivers immediate, significant benefits to companies who are dealing with data management, data movement, and data availability issues.

"By creating a universal namespace, users are never disrupted and administrators can change, add, grow, or shrink without ever affecting the environment."

Steve Duplessie, Enterprise Storage Group

Table 1

Requirements                     How StorageX and VFM Meet
                                 the Requirements

* Tools for namespace            * Discover shares and automatically
  creation and population          construct a name-space that the
                                   administrator can modify as needed

* Ability to synchronize         * The namespace is automatically
  the namespace with the           updated when storage is added, moved,
  underlying physical storage      changed, or reconfigured

* Namespace monitoring and       * Provide distributed file system
  management                       and namespace monitoring and
                                   management from a single console

* High availability of the       * The namespace can be clustered for
  namespace                        high availability and to eliminate
                                   any single points of failure

* Easy to change or reconfigure  * Both products provide simple
  the namespace when needed        processes for non-disruptive
                                   namespace reconfiguration

Table 2

Traditional Server/                     Global Namespace-Enabled
Storage Consolidation                   Consolidation

* Plan downtime and inform              * Migrate data to new location
  users                                 * Decommission old servers
* Migrate files                           and storage
* Edit login scripts                    * Total administrative
* Edit backup tasks                       time: 3-5 hours
* Inform users of new locations
  and file shares
* Have all users re-login
* Field user calls for broken
  mapped drives and shortcuts
* Field user calls for broken
  applications
* Locate and correct all dependent
  applications
* Decommission old servers and storage
* Total administrative time: 3-5 days