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Scheduling a Parity Check

Choose Array Administration > Schedule Parity Check to check parity of a specific logical array at scheduled intervals (for example, during off hours). Depending on which options you select, the parity can be overwritten and any error reported as an event.

  • You can choose to schedule any number of logical drives configured on a managed server; however, you can establish only one schedule per array controller.
  • When you schedule multiple logical drives, the check is done in sequence from the lowest to the highest numbered logical drive.
  • A parity check requires an average of five minutes per Gbyte of storage.
  • You can control the amount of resources allocated to the parity check by changing the rebuild priority. See Rebuild Priority.
  • A parity check can be stopped once it has started.
  • There is no data corruption as a result of this operation.

    Creating a Parity Check Schedule:

    1. Select the controller on which you want to schedule the parity check.
    2. Choose Array Administration > Schedule Parity Check.
    3. NOTE: You need to be logged in as either ssadmin or ssconfig to access options on this menu.

      The Schedule Parity Check window is displayed.

    4. Make selections in the appropriate fields.
      • Listed Logical Drives - A list of the available fault-tolerant logical arrays. Use the Shift key to select multiple drives.
        • Regenerate - For RAID 3 and 5 configurations, the parity checking procedure on a logical drive recalculates the parity of data stripes in each of the logical drive’s RAID stripe sets and compares it with the stored parity. If a discrepancy is found, the new correct parity is substituted for the stored parity. For RAID 1 configurations, if an inconsistency is encountered, data is copied from the master disk to the slave disk. If a bad block is encountered when the parity is regenerated, the data is copied from the other disk, master or slave, to the reporting disk drive reallocating the bad block.
        • NOTE: If you select Regenerate, make sure that Generate Error Event is also selected.

        • Generate Error Event (default) - When a parity check is run and a discrepancy is found, an error is reported, which enables you to analyze the error and check the integrity of your data before overwriting the parity drive.

        CAUTION: If an array's data parity is seriously damaged, restoring data by regenerating might cause data loss. Only select Regenerate after you have performed any necessary data recovery based on the parity check errors.

      • Rebuild Priority - The amount of resources allocated to perform a rebuild (low, normal, improved, high). Select Change Controller Parameters from the Custom Configuration Options window to change the rebuild priority.

      • How Often - How often you want the parity checked.
      • Starting Day - The day of the week you would like this schedule to start.
      • Starting Time - The time on the starting day you would like this schedule to begin.
      • Existing Schedule - The current parity schedule: logical drive, frequency, starting day, and time.
      • Next Parity Check - The date and time you want the next parity check to start.

    5. When you are satisfied with the schedule, click OK.
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