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Creating a mirrored aggregate

You can use the aggr create command to create a mirrored aggregate. You have several options for how to specify the disks or array LUNs when you create a mirrored aggregate.

About this task

When you create an aggregate, you can specify the aggregate to use SyncMirror. This ensures that the aggregate is a mirrored one from the start.
There are three methods of creating a mirrored aggregate:
  • Ascertaining the disks or array LUNs available, and specify which ones to use.
  • Allowing Data ONTAP to automatically use the disks or array LUNs that are available.
  • Previewing the disks or array LUNs that Data ONTAP has selected. Then, you can either use the same selection or modify the selection.

Steps

  1. You can use the aggr create command to create a mirrored aggregate. As required, choose one of the actions from the following table.
    If... Then...
    You know the disks or array LUNs to be used for the mirrored aggregate, and want to specify the disks Enter the following command:aggr create aggr_name -m -d disk-list -d disk-listEnsure that you choose the correct number and size of disks for each set of disks.
    Note: Both the -d options must be used, one for each plex. If you specify only one disk set, the creation of a mirrored aggregate fails.

    This step completes the creation of a mirrored aggregate.

    You want Data ONTAP to select the disks for the mirrored aggregate Go to the next step.
    Note: Allowing Data ONTAP to select the disks is the easiest method of creating a mirrored aggregate.
    aggr_name is the name of the mirrored aggregate.

    -m specifies the creation of a mirrored aggregate.

    disk-list consists of the disk IDs of two or more available disks. You should separate multiple disks with the space character.

    Example
    The following command creates a mirrored aggregate named aggrA with disks 6.1 and 6.2 on one plex, and disks 8.1 and 8.2 on the other plex:aggr create aggrA -m -d 6.1 6.2 -d 8.1 8.2
  2. As required, choose one of the actions from the following table.
    If you want... Then enter the following command...
    Data ONTAP to automatically specify the disks for the mirrored aggregate aggr create aggr_name -m ndisks[@disk-size]

    This step completes the creation of a mirrored aggregate.

    To preview the disks selected by Data ONTAP for creating the mirrored aggregate aggr create aggr_name -n -m ndisks[@disk-size]
    Note: The -n option instructs Data ONTAP not to create the aggregate, but to display the disks selected automatically for creating the mirrored aggregate.
    The system displays an aggr create command indicating the disks to be used for the mirrored aggregate.

    Go to the next step.

    ndisks is the number of disks to use, which must be a minimum of four and an even number. Even numbers are required because the disks are equally divided between the two plexes.
    disk-size specifies the disk capacity, in gigabytes. There must be enough disks of this size available.
    Note: If you want to specify the disk size, first determine the size of spare disks in the disk pools by using the vol status -r command.
    Example
    The following command creates a mirrored aggregate named aggrB, with two plexes, each plex containing three disks.aggr create aggrB -m 6
  3. As required, choose one of the actions from the following table.
    If you want to... Then...
    Use the selection provided in the preview Enter the aggr create command, displayed by the system in the previous step.
    Change one or more of the disks provided in the preview Enter the aggr create command, displayed by the system in the previous step. Substitute one or more disks with other disks that you want to specify.
    Example
    The following command displays the aggr create command, with a preview of the disk selection for creating a four-disk mirrored aggregate named aggrC.aggr create aggrC -n -m 4The system returns the following command:
    aggr create aggrC -m -d 5.1 5.3 -d 8.3 8.4
    Use the preceding command to create a mirrored aggregate named aggrC, with two disks in each plex.
    For more information about aggregates, see the Data ONTAP Storage Management Guide for 7-Mode.