Creating a disk array

A disk array is created using a set of Active Array Candidate pdisks.

About this task

For disk arrays with data redundancy (RAID 5, 6, 10, 5T2, 6T2, and 10T2), if all of the pdisks are in the Zeroed state, the array will become immediately protected against failures. However, if one or more of the pdisks are not Zeroed, the newly created array will initially be in the Rebuilding state. It will be unprotected against disk failures until parity data on all of the disks has been recalculated. Ensure that all pdisks are placed in a Zeroed state by selecting Create an Array Candidate pdisk and format to RAID block size before creating a disk array to fully initialize the pdisks and provide the shortest time to create the disk array.
A RAID array must be entirely composed of devices from the same device class. Multiple disk arrays, consisting of different device classes, may coexist on the same controller. The following are the supported device classes:
  • 528 HDDs (10K or 15K)
  • 4K HDDs (10K or 15K)
  • 4K Nearline HDDs
  • 528 SSDs
  • 4K SSDs
  • 528 Read Intensive (Mainstream) SSDs
  • 4K Read Intensive (Mainsteam) SSDs

To create a IBM® SAS Disk Array, complete the following steps:

Procedure

  1. Start the IBM SAS Disk Array Manager by following the steps in Using the Disk Array Manager.
  2. Select Create a IBM SAS Disk Array.
  3. Select the appropriate IBM SAS RAID Controller on which you want to create an array.
  4. Select the RAID level for the array.
    For more information about selecting an appropriate RAID level, see Supported RAID levels.
  5. Select the stripe size in kilobytes for the array.
    For more information about the stripe-size parameter, see Stripe-unit size.

    A selection screen similar to the following representation displays. You can view a list of Array Candidate pdisks and notes regarding array requirements. The screen displays information about the minimum and maximum number of supported disks, the minimum number of disks required in each tier, the minimum percent of total array capacity required in each tier, along with any other specific requirements for the array. Note that the screen always shows information related to tiered RAID levels even if you selected a non-tiered RAID level. In the case of a non-tiered RAID level, then the tiering requirements will display zeros and can be ignored. Select the disks that you want to use in the array, including disks for all tiers, according to the requirements on this screen.

    
+--------------------------------------------------------------------------+
|                     Select Disks to Use in the Array                     |
|                                                                          |
| Move cursor to desired item and press F7. Use arrow keys to scroll.      |
|     ONE OR MORE items can be selected.                                   |
| Press Enter AFTER making all selections.                                 |
|                                                                          |
|   # RAID 5 supports a minimum of 3 and a maximum of 18 drives.           |
|   # RAID 5 allows each tier to contain a minimum of 0 disks              |
|   # and 0 percent of the total array capacity.                           |
|                                                                          |
|                                                                          |
|   pdisk1    00040200  Active      Array Candidate         34.8GB Zeroed  |
|   pdisk3    00040900  Active      Array Candidate         34.8GB Zeroed  |
|   pdisk4    00040000  Active      Array Candidate         34.8GB Zeroed  |
|   pdisk5    00040300  Active      Array Candidate         34.8GB Zeroed  |
|                                                                          |
| F1=Help                 F2=Refresh              F3=Cancel                |
| F7=Select               F8=Image                F10=Exit                 |
| Enter=Do                /=Find                  n=Find Next              |
+--------------------------------------------------------------------------+

    A SMIT Dialog Screen summarizes your selections.

  6. Press Enter to create the array.

Results

You can now add the disk array to a volume group. Logical volumes and file systems can also be created. Use standard AIX® procedures to perform these tasks, and treat the array in the same way that you would treat any hdisk.