3Ware 9550SXU16MLB10 User Guide - Page 60

3ware Disk Manager (3DM 2) processing time will be given to background tasks rather than I/O. The furthest right buttons set the firmware to the slowest background rates, giving maximum processing time to I/O. For additional information, see"Setting Background Task Rate" on page 124. Unit Policies For units on 9000-series controllers, you can enable or disable three policies: Write Cache, Auto-verify and Continue on Source Error During Rebuild. 3DM lists each unit on the controller specified in the drop-down list on the menu bar, and shows you whether the policies are currently enabled or disabled for each unit. This section does not appear for 7000- and 8000- series controllers. Unit Write Cache. You can enable or disable write cache for each unit. 3DM lists each unit on the controller specified in the drop-down list on the menu bar, and shows you whether the write cache is currently enabled or disabled for it. Write cache is a combination of the physical hard drives' write cache as well as the controller's memory, depending on what type of unit you are using. For 9000-series controllers, a Disable Write Cache on Unit Degrade setting can be set in 3ware BIOS Manager (3BM). You can see if this setting is enabled in the Other Controller Settings field at the bottom of this Controller Settings page. If Disable Write Cache on Unit Degrade is enabled, upon degrade of a unit, the write cache will automatically be disabled, even if you enable write cache in the Unit Write Cache field. For additional information, see "Enabling and Disabling the Unit Write Cache" on page 95 Auto-verify. The Auto-verify policy causes verify tasks to be performed automatically, whenever the controller firmware algorithms determine that a verify task is needed. This feature is designed to make verification of units easier. When you check this box, the controller will run verify tasks as they are required. If there is no schedule set up for verify tasks, then the controller firmware can initiate a verify task at any time. If a verify time window is scheduled, then the controller will not start a verify task for that unit outside the time window, and may or may not start a verify task for that unit within the time window, depending on whether one is needed. If Auto-verify is not set and there is no schedule, you must manually specify when you want to run a verify, on the 3DM Management page. Continue on Source Error During Rebuild. This policy applies only to units which are redundant. (For units which are not redundant, a check box is not available.) When this policy is set, ECC errors are ignored when they are 54 3ware 9000 Series Serial ATA RAID Controller User Guide