Chapter 1. Introducing the 3ware® 9000 Series Controller12 3ware 9550SX Serial ATA RAID Controller User GuideMonitoring, Maintenance, andTroubleshooting FeaturesSeveral 3ware RAID controller features aid in monitoring andtroubleshooting your drives. SMART Monitoring (Self-Monitoring, Analysis and ReportingTechnology) automatically checks a disk drive's health every 24 hoursand reports potential problems. This allows you to take proactive steps toprevent impending disk crashes. SMART data is checked on all diskdrives (array members, single disks, and hot spares). Monitoring ofSMART thresholds can be turned on and off in 3DM. (For details, see“Viewing SMART Data About a Drive” on page 168.) Staggered Spinup allows drives that support this feature to be powered-up into the standby power management state to minimize in-rush currentat power-up and to allow the controller to sequence the spin-up of drives.Both SATAII OOB and ATA spin-up methods are supported. The standbypower management state is persistent after power-down and power-up.You can set the number of drives that will spin up at the same time, andthe time between staggers in 3BM (the 3ware BIOS Management utility).For details, see “Enabling and Setting Up Staggered Spinup” on page 120. Verification and Media Scans. The verify task verifies all redundantunits, and checks for media errors on single disks, spares, JBODS andRAID 0 unit members. If the disk drive is part of a redundant unit, errorlocations that are found and are deemed repairable are rewritten with theredundant data. This forces the drive firmware to reallocate the errorsectors accordingly. Error Correction. Bad sectors can be dynamically repaired through errorcorrection (Dynamic Sector Repair). Reallocation of blocks will try to bebased intelligently on the location of the block in relation to the stripe. Scheduled Background Tasks. Initialize, rebuild, verify, and self-testtasks can all be run in the background, at scheduled times. This lets youchoose a time for these tasks to be run when it will be least disruptive toyour system. You can also define the rate at which background tasks areperformed, specifying whether I/O tasks should be given more processingtime, or background rebuild and verify tasks should be given moreprocessing time. Write Cache. Write cache can be enabled or disabled using 3BM 2,3DM 2 and CLI. When write cache is enabled, data will be stored insystem cache, 3ware controller cache, and drive cache before the data iscommitted to disk. This allows the system to process multiple writecommands at the same time, thus improving performance. However whendata is stored in cache, it could be lost if a power failure occurred. With a
