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Expanding the Capacity of a Logical Drive or Logical Volume

Use this option to expand the capacity of an existing logical drive, or to expand the capacity of a logical volume. For example, you might originally have had an 18-Gbyte drive of which only 9 Gbyte were selected to build a logical drive. To use the remaining 9 Gbyte, you must expand the logical drive. RAID levels 0, 1, 3, and 5 support expansion.

NOTE: To expand a logical volume, you must first expand the logical drives that make up the logical volume.

  1. Select the array that you want to configure.
  2. Choose Configuration > Custom Configure.
  3. Select Dynamically Grow and/or Reconfigure LDs/LVs from the Custom Configuration Options window.
  4. Select the logical drive or logical volume you want to expand.
  5. Select the Expand LD/LV tab.
  6. Specify the capacity in Mbyte by which you want to expand the logical drive or logical volume in the Maximum Drive Expand Capacity field, and click OK.

    The capacity shown in the Maximum Available Drive Free Capacity field is the maximum available free disk space per physical drive, based on the smallest physical drive in the logical drive. The capacity you specify is added to each physical drive in the logical drive.

    As described in the following examples, the total amount of capacity that is added to the logical drive is calculated automatically based on the RAID level.

    NOTE: Spare drives are not included when expanding a logical drive. Do not include spare drives when calculating maximum drive expand capacity.

    • RAID 0 - Multiply the amount entered in the Maximum Drive Expand Capacity field by the total number of physical drives contained in the logical drive. For example, 100 Mbyte x 3 = 300 Mbyte total capacity added to the logical drive.

    • RAID 1 - Multiply the amount entered in the Maximum Drive Expand Capacity field by the total number of physical drives contained in the logical drive, and then divide by two to account for mirroring. For example, 100 Mbyte x 4 = 400 Mbyte. 400/2 = 200 Mbyte total capacity added to the logical drive.

    • RAID 3 and 5 - Multiply the amount entered in the Maximum Drive Expand Capacity field (c) by the total number of physical drives contained in the logical drive, and then subtract c to account for parity. For example, if c = 100, 100 Mbyte x 3 = 300 Mbyte. 300 Mbyte - 100 Mbyte = 200 Mbyte total capacity added to the logical drive.

    If you know the total maximum drive capacity by which you want to expand a logical drive, perform the following calculations based on the RAID level to determine the amount to enter in the Maximum Drive Expand Capacity field:

    • RAID 0 - Divide the total maximum drive capacity by the total number of physical drives contained in the logical drive. For example, if you want to add a total of 100 Mbyte to a logical drive that contains four physical drives, 100 Mbyte/4 = 25 Mbyte maximum drive expand capacity.

    • RAID 1 - Divide the total number of physical drives contained in the logical drive by two to get n. Then divide the maximum drive capacity by n. For example, if you want to add a total of 100 Mbyte to a logical drive that contains four physical drives, 4/2 = 2. 100/2 = 50 Mbyte maximum drive expand capacity.

    • RAID 3 and 5 - Subtract a single drive from the total number of physical drives to get n. Then divide the total maximum drive capacity by n. For example, if you want to add a total of 100 Mbyte to a logical drive that contains five physical drives, 5-1 = 4. 100/4 = 25 Mbyte maximum drive expand capacity.

    NOTE: The Maximum Drive Expand Capacity cannot exceed the Maximum Available Drive Free Capacity.

  7. To use the logical drive immediately, select OnLine Expansion.

    Online expansion enables you to use the logical drive before expansion is complete. However, because the controller is building the logical drive while performing I/O operations, expanding a logical drive online requires more time than offline expansion.

    If you do not select OnLine Expansion, you can use the drive only after expansion is complete. Because the controller is building the logical drive without having to also perform I/O operations, offline expansion requires less time than online expansion.

    NOTE: The Online Expansion option is not available when expanding logical volumes.

  8. Click OK in the Confirm Configuration Operation window to complete the operation.

The Logical Drive/Logical Volume Number

For important information regarding the logical drive/logical volume number displayed in the LD/LV field in the Dynamically Grow and/or Reconfigure LDs/LVs window, see The Logical Drive/Logical Volume Number.

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