Ensuring Business Continuance via High Availability SANs Page 3
LAN Constraint Freedom
Storage consolidation creates a common pool of storage that is shared among all servers; thus, one or more new or existing tape libraries can easily (and without disruption) be connected to the SAN. They are also controlled by a dedicated backup server running backup application software (such as VERITAS NetBackup or Tivoli Storage Manager). All backups are managed from this server via an intuitive graphical user interface, thus allowing an administrator to manage a larger number of servers.
Through the automation of the entire process, a single administrator can also manage the backup of thousands of users connected to numerous servers while benefiting from a reduction in day-to-day monitoring and having to respond to exception conditions. With numerous scheduling options for frequency, administrators can now define backups as full, incremental, or differential. Formal data protection policies can also be defined within the backup application to ensure consistent protection across the enterprise.
Most backup applications are database-aware, which allows for non-disruptive backups of online databases with minimal impact to CPU performance. Prior to the backup, backup agent processes running on each server establish snapshots or transparent split-mirror copies of each database. The data from servers may then be backed up to the tape library by applications that deliver multiple data streams from all servers simultaneously. So, with only minimal command traffic sent over the LAN, all backup data traffic is routed over the SAN. For server-specific off-site backup or co-location support, some backup applications can also automatically create multiple copies of a backup or de-multiplex a tape.
Since each element of the data protection solution is scalable, administration and management of future growth is greatly simplified. Without disruption, each server attached to the SAN may quickly allocate additional storage as required from the existing central pool. In order to accommodate future needs, the storage, tape libraries, control processors, and the SAN itself can be flexibly and extensively scaled as necessary.
For server-less backup, a true data protection solution offers complete hardware and application support. Without first sending the data through the production application server's CPU, each disk device receives instructions to copy data directly to the tape device. By conveying data directly to the backup device, server-less backup significantly reduces the application server's CPU overhead and accelerates the backup process.
A true data protection solution significantly improves productivity by ensuring higher availability of data throughout the backup process and rapid access to and restoration of lost data. This is in addition to the greater protection realized with more reliable and frequent backups. By shifting backup traffic to the SAN and extending the LAN's useful life, the existing LAN's performance is dramatically improved.
Finally, a robust data protection solution delivers a rapid return on investment that can be measured in just a few months, not years. While the need for new backup device purchases for each new server is eliminated, existing hardware investments can be better utilized. Storage that was once individually connected to each server gains higher utilization when centralized, while the associated cost of management and administration is reduced proportionately. Most importantly, the cost of downtime due to data protection or loss is significantly reduced or virtually eliminated, which of course directly contributes to the bottom line of the business.