RAIDTo be of any value, hard drive reliability is critical. HardwareRAID is an approach that protects you against disk failure.RAID systems can be configured to spread or stripe dataacross a set of drives, which not only prevents data loss dueto failure of an individual drive, but also improves overall system performance. However, even the best RAID isn’t perfect; for instance, while it’s unlikely, two disks could fail at the same time, or the controller could develop a fault. Nevertheless, a properly configured RAID will be invaluable asset, especially on larger networks.The following are different RAID levels. The three most commonare 0, 3, and 5, with each level having its own advantages anddrawbacks.Level 0—Provides data striping (spreading out blocks ofeach file across multiple disks) but no redundancy. Thisimproves performance but doesn’t deliver fault tolerance.Level 1—Provides disk mirroring (a technique in which datais written to two duplicate disks simultaneously).Level 3—Same as Level 0, but also keeps one dedicateddisk for error correction data. This provides good performanceand a low level of fault tolerance.Level 5—Provides data striping at the byte level and alsostripe error correction information, which results in excellentperformance and good fault tolerance.