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Customize the size of your RAID groups in ONTAP

Contributors netapp-thomi netapp-lenida netapp-aherbin
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You can customize the size of your RAID groups to ensure that your RAID group sizes are appropriate for the amount of storage you plan to include for a local tier.

Note Prior to ONTAP 9.7, System Manager uses the term aggregate to describe a local tier. Regardless of your ONTAP version, the ONTAP CLI uses the term aggregate. To learn more about local tiers, see Disks and local tiers.
About this task

For standard local tiers, you change the size of RAID groups for each local tier separately. For Flash Pool local tiers, you can change the RAID group size for the SSD RAID groups and the HDD RAID groups independently.

The following list outlines some facts about changing the RAID group size:

  • By default, if the number of disks or array LUNs in the most recently created RAID group is less than the new RAID group size, disks or array LUNs will be added to the most recently created RAID group until it reaches the new size.

  • All other existing RAID groups in that local tier remain the same size, unless you explicitly add disks to them.

  • You can never cause a RAID group to become larger than the current maximum RAID group size for the local tier.

  • You cannot decrease the size of already created RAID groups.

  • The new size applies to all RAID groups in that local tier (or, in the case of a Flash Pool local tier, all RAID groups for the affected RAID group type—​SSD or HDD).

Steps

  1. Use the applicable command:

    If you want to…​

    Enter the following command…​

    Change the maximum RAID group size for the SSD RAID groups of a Flash Pool local tier

    storage aggregate modify -aggregate aggr_name -cache-raid-group-size size

    Change the maximum size of any other RAID groups

    storage aggregate modify -aggregate aggr_name -maxraidsize size
Examples

The following command changes the maximum RAID group size of the local tier n1_a4 to 20 disks or array LUNs:

storage aggregate modify -aggregate n1_a4 -maxraidsize 20

The following command changes the maximum RAID group size of the SSD cache RAID groups of the Flash Pool local tier n1_cache_a2 to 24:

storage aggregate modify -aggregate n1_cache_a2 -cache-raid-group-size 24