Disk Subsystem Single Points of Failure

For years, high availability and disaster recovery have been focused on the data that resides on disk subsystems. Disk subsystems, due to the physically moving disk drives themselves, represent by far the most common failure point in computing systems. In fact, it is because of this shortcoming that RAID (redundant array of inexpensive/independent disks) came to be.

Disk Drives and RAID

Different levels of RAID exist, each with its own advantages and disadvantages. Some of the most common implementations include:

  • RAID 1, or mirroring. Here, a physical drive “mirrors” a second drive. Thus, for every two drives paid for and installed, only one is effectively “used” for data—for this reason, it is the most ...

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