3Ware 9550SXU-12 User Guide - Page 29

Monitoring, Maintenance, and Troubleshooting Features • Verification and Media Scans. The verify task verifies all redundant units, and checks for media errors on single disks, spares and RAID 0 unit members. If the disk drive is part of a redundant unit, error locations that are found and are deemed repairable are rewritten with the redundant data. This forces the drive firmware to reallocate the error sectors accordingly. (For more information, see "About Verification" on page 162.) • Error Correction. Bad sectors can be dynamically repaired through error correction (Dynamic Sector Repair). Reallocation of blocks is based intelligently on the location of the block in relation to the stripe. • Scheduled Background Tasks. Initialize, rebuild, verify, and self-test tasks can all be run in the background, at scheduled times. This lets you choose a time for these tasks to be run when it will be least disruptive to your system. You can also define the rate at which background tasks are performed, specifying whether I/O tasks should be given more processing time, or background rebuild and verify tasks should be given more processing time. (For more information, see "Scheduling Background Tasks" on page 173.) • Write Cache. Write cache can be enabled or disabled using 3BM, 3DM 2 and CLI. When write cache is enabled, data will be stored in 3ware controller cache and drive cache before the data is committed to disk. This allows the system to process multiple write commands at the same time, thus improving performance. However when data is stored in cache, it could be lost if a power failure occurs. With a Battery Backup Unit (BBU) installed, the data stored on the 3ware controller can be restored. (For more information, see "Enabling and Disabling the Unit Write Cache" on page 118.) • StorSave™ Profiles allow you to set the level of protection versus performance that is desired for a unit when write cache is enabled. (For more information, see "Setting the StorSave Profile for a Unit" on page 123.) • Enclosure Services. Drives, fans, temperature sensors, and power supplies in supported enclosures can be identified by flashing LEDs so that you can quickly identify which component needs to be checked or replaced. For more information, see "Managing an Enclosure" on page 206. • Auto Rebuild. For times when you do not have a spare available, setting the Auto Rebuild policy allows rebuilds to occur with an available drive or with a failed drive. (For more information, see "Setting the Auto Rebuild Policy" on page 91.) www.3ware.com 17