MegaRAID Storage Manager Online Help System

Configuration > Creating a New Configuration > Manual Configuration

Manual Configuration

Manual Configuration allows you the greatest level of control in creating a new configuration. The first Manual Configuration screen has a panel on the left showing the unconfigured physical drives that are available to create a new array. The right panel shows new arrays as you define them. It also shows existing arrays that have “holes” (free space that can be used to form new virtual disks).

Step 1: Defining New Arrays

To define new arrays with the Manual Configuration option, follow these steps:

  1. Select available drives in the left panel. You can Shift-click to select a range of drives, or Ctrl-Click to select multiple drives individually. Click the Add button below the panel to move the drives to the right panel.
  2. When you have selected all the drives you want for the array, click Accept to accept these drives for the new array.
  3. Select drives for another array, if desired, and click Accept.
  4. To add a dedicated hotspare to an array, select an available drive in the left panel, select the array from the drop-down panel, and click Add HotSpare To.
  5. If the hotspare disk is in a disk enclosure, the Select Affinity Option window appears. The choices are as follows:
    • With affinity: If a disk in the enclosure fails, this hotspare will have the first priority to replace it.
    • No affinity: The hotspare will not have a special priority to replace failed disks in this enclosure.
    • To remove all physical drives from a proposed array, select the New Array icon in the right panel and click the left-pointing button. To remove a single drive from a proposed array, select the drive icon in the right panel and click the left-pointing button. To remove a dedicated hotspare from an array, select it in the right panel and click Remove HotSpare.

  6. Click Next to continue with the next configuration step.
Step 2: Defining Virtual Disks

In the next Manual Configuration screen the scrolling menu in the upper middle panel shows arrays with available space—both the array(s) you defined on the previous screen and any existing arrays with “holes” (free space).

You cannot create virtual disks with different RAID levels on a single array.

  1. Click check boxes in the menu to select arrays and “holes” that you want to use for the new virtual disk. Select multiple RAID 0, RAID 1, or RAID 5 arrays to create a spanned array.
  2. When you have selected all the space you need for the virtual disk, change the default virtual disk properties in the right panel, if needed. The properties are as follows:
    • RAID Level: MegaRAID Storage Manager supports RAID 0, 00, 1, 10, 5, 50, and 6. (See Understanding RAID Levels.) The menu lists only the RAID levels that are possible, given the number of disks you have selected and other factors. For example, RAID 0 is not on the menu if you selected a hot spare on the previous screen. Spanned arrays use either RAID 00, RAID 10 or RAID 50. For more information about spanned arrays, see Creating a Spanned Disk Array.
    • Size: The available space on the array will vary, depending on the RAID level.
    • Volume ID: Options range from 0 to 63. If an ID has already been assigned to another virtual disk, it does not appear on the menu.
    • Volume Name: The volume name must be no more than 16 characters.
    • Stripe Size: Stripe sizes ranging from 8KB to 1MB are supported. The default is 64KB.
    • Read Policy:
      Always read ahead: Read-ahead capability allows the controller to read sequentially ahead of requested data and to store the additional data in cache memory, anticipating that the data will be needed soon. This speeds up reads for sequential data, but there is little improvement when accessing random data.
      No read ahead: Disables the read-ahead capability.
      Adaptive read ahead: When selected, the controller begins using read-ahead if the two most recent disk accesses occurred in sequential sectors. If the read requests are random, the controller reverts to No read ahead.
    • Default Write Policy:
      Write back: In this mode the controller sends a data transfer completion signal to the host when the controller cache has received all the data in a transaction. This setting is recommended in standard mode.
      Write through: In this mode the controller sends a data transfer completion signal to the host when the disk subsystem has received all the data in a transaction.
    • Use Write Through for Failed or Missing Battery:
      Select this option if you want the controller to default to write through mode if an battery backup unit fails or is removed.
    • IO Policy: The IO Policy applies to reads on a specific logical drive. It does not affect the Read-ahead cache.
      Cached IO: In this mode, all reads are buffered in cache memory.
      Direct IO: In this mode, reads are not buffered in cache memory. Data is transferred to cache and the host concurrently. If the same data block is read again, it comes from cache memory.
    • Access Policy: Select the type of data access that is allowed for this logical drive: Read/Write, Read Only, or Blocked.
    • Disk Cache Policy: Select a cache setting for this disk: Unchanged, Enabled, or Disabled.
    • Init State: Select from No Init (do not initialize the disk at this time), Quick Init (initialize the first and last regions of the disk), or Full Init (initialize the entire disk).
    • You can change the virtual disk properties later after the disk is created by selecting Operations >> Set Virtual Disk Properties.

  3. Click Accept to accept the configuration of the new virtual disk, which appears on the screen.
  4. Click the Reclaim button if you want to undo a virtual disk that you just defined.

  5. Select available space and for another virtual disk, define its properties, and click Accept. Or click Next to continue with the next configuration step.
  6. The next screen is a virtual disk summary.
Step 3: Accepting the Configuration
  1. Review the configuration shown on the screen. If you want to change something, click Back and change the configuration parameters.
  2. If the configuration is acceptable, click Finish to accept it and to start the actual initialization process (unless you selected the No Init option on the previous screen).

DB09-000202-00  July 2007
Copyright© 2007 by LSI Corporation. All rights reserved.
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