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Creating an aggregate

You create an aggregate to provide storage to one or more FlexVol volumes (or one traditional volume).

Before you begin

Determine the name of the aggregate. Aggregate names must conform to the following requirements:
  • Begin with either a letter or an underscore (_)
  • Contain only letters, digits, and underscores
  • Contain no more than 250 characters
Note: You can change the name of an aggregate later by using the aggr rename command.
Determine what disks or array LUNs will be used in the new aggregate. You can specify disks by listing their IDs, or by specifying a disk characteristic such as speed or type. You can display a list of the available spares on your storage system by using the aggr status -s command.
Note: If your storage system is attached to more than one type of disk, or to both disks and array LUNs, and you do not use the -T option, Data ONTAP creates the aggregate using the disk type (including array LUNs) with the highest number of available disks. To ensure that Data ONTAP uses the disk type that you expect, always use the -T option when creating aggregates from heterogeneous storage.


  1. Enter the following command:aggr create aggr_name [-f] [-m] [-n] [-t {raid0 | raid4 | raid_dp}] [-r raidsize] [-T disk-type] -R rpm] [-L] [-B {32 | 64}] disk-list

    aggr_name is the name for the new aggregate.

    -f overrides the default behavior that does not permit disks in a plex to belong to different disk pools. This option also allows you to mix disks with different RPM speeds even if the appropriate raid.rpm option is not off.

    -m specifies the optional creation of a SyncMirror-replicated volume if you want to supplement RAID protection with SyncMirror protection. A SyncMirror license is required for this feature.

    -n displays the results of the command but does not execute it. This is useful for displaying the disks that would be automatically selected prior to executing the command.

    -t {raid0 | raid4 | raid_dp} specifies the level of RAID protection you want to provide for this aggregate. If no RAID level is specified for an aggregate composed of disks, the default value (raid_dp) is applied. raid0 is used only for array LUNs.

    -r raidsize is the maximum size of the RAID groups for this aggregate. If no size is specified, the default is used.

    -T disk-type specifies one of the following types of disk to be used: ATA, SATA, SAS, BSAS,FCAL, or LUN. This option is only needed when creating aggregates on systems that have mixed disk types or both disks and array LUNs. Use SATA for SAS-attached ATA disks, SAS for SAS-attached SAS disks, FCAL for FC disks, ATA for ATA disks connected through FC-AL, and LUN for array LUNs.
    Note: If the raid.disktype.enable option is set to off (its default value), FCAL and SAS disks are considered to be the same type for the purposes of creating an aggregate and may be combined even if the -T option is used. Similarly, ATA, BSAS, and SATA disks are considered to be the same type and may be combined, even when the -T option is used.

    -R rpm specifies the type of disk to use based on its speed. Valid values for rpm include 5400, 7200, 10000, and 15000.

    -B {32 | 64} specifies the type of the aggregate: 32-bit or 64-bit. The default value is 32. The type of the aggregate determines its maximum size and the type of the FlexVol volumes it contains. The aggregate type cannot be changed after the aggregate is created.
    Note: The presence of 64-bit aggregates on the storage system prevents that system from being reverted to releases earlier than Data ONTAP 8.0.
    disk-list is one of the following values:
    • ndisks[@disk-size]

      ndisks is the number of disks to use. It must be at least 3 for RAID-DP aggregates, 2 for RAID-4 aggregates, or 1 for RAID0 aggregates.

      disk-size is the disk size to use, in gigabytes.

    • -d disk_name1 disk_name2... disk_nameN

      disk_name1, disk_name2, and disk_nameN are disk IDs of available disks; use a space to separate disk IDs.


The following command creates an aggregate called newaggr, with a RAID group size of 8, consisting of the disks with disk IDs 8a.16, 8a.17, 8a.18, and 8a.19:aggr create newaggr -r 8 -d 8a.16 8a.17 8a.18 8a.19

The following command creates an aggregate called newfastaggr, with 20 disks, the default RAID group size, and all disks with 15K RPM:aggr create newfastaggr -R 15000 20

The following command creates an aggregate called newFCALaggr. Note that if SAS disks are present, they might be used, because FC and SAS disks are considered to be the same type.aggr create newFCALaggr -T FCAL 15

After you finish

You can use the aggr status -r command to verify the RAID groups and disks used in the aggregate you just created.

Related concepts
Considerations for sizing RAID groups for disks
Considerations for Data ONTAP RAID groups for array LUNs
Protection provided by RAID and SyncMirror
How aggregates work
How Data ONTAP uses RAID to protect your data and data availability
How you can use disks with mixed speeds in the same aggregate
Related reference
Storage limits