Recovering from a System Failure


Having data stored on a SAN or NAS device can greatly reduce recovery time for failed systems. By having replicas of data on other devices, data can be reattached to a system in case of a system failure. In the situation where a server was booting its operating system off a SAN device, the Host Bus Adapter can simply be placed in similar hardware and the system will come right back up.

In the case of system failure due to data corruption, a SAN or NAS will enable you to roll the system back to a point in time before the corruption occurred based on the number of snapshots available.

If a system fails due to actual disk failure on the VLD or LUN that it was attached to, a system can be brought back up quite quickly if the data on that VLD or LUN was mirrored to another NAS or SAN device. By simply remapping the VLD or LUN the system can be made functional again in a very rapid manner.

Mirroring and snapshotting are the keys to using NAS or SAN to make a system more easily recoverable than it would have been with DAS. Simple planning like keeping servers standard in their brand and configurations, always using the same brand and model of HBA or NIC, and keeping Fiber Channel switches standard across the enterprise enables you to have an environment where failed components can be replaced from a standard set of spare parts and the system brought up immediately.

Even in cases where entire sites fail due to storm , earthquake, or fire, systems can be brought back up quite rapidly in a failover location if the data was mirrored. Using SAN or NAS to perform this mirroring ensures a much greater level of confidence that the data was replicated correctly, even for databases that remain hot on a 24 by 7 schedule. Recoverability from both a site and a system level make SAN or NAS integrated environments much more resilient and reliable.



Microsoft Windows Server 2003 Insider Solutions
Microsoft Windows Server 2003 Insider Solutions
ISBN: 0672326094
EAN: 2147483647
Year: 2003
Pages: 325

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