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Increase the size of ONTAP FlexGroup volumes

Contributors netapp-lenida netapp-dbagwell johnlantz netapp-barbe netapp-thomi netapp-aherbin
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You can increase the size of a FlexGroup volume either by adding more capacity to all existing member volumes (constituents) of the FlexGroup volume or by expanding the FlexGroup volume with new member volumes. A FlexGroup volume cannot have more than 200 member volumes.

You can also increase the size of an individual volume within a FlexGroup volume if needed.

Before you begin

Sufficient space must be available in the aggregates.

About this task

If you want to add more space, you can increase the collective size of the FlexGroup volume. Increasing the size of a FlexGroup volume resizes the existing member volumes of the FlexGroup volume.

If you want to improve performance, you can expand the FlexGroup volume. You might want to expand a FlexGroup volume and add new member volumes in the following situations:

  • New nodes have been added to the cluster.

  • New local tiers (aggregates) have been created on the existing nodes.

  • The existing member volumes of the FlexGroup volume have reached the maximum FlexVol size for the hardware (100TB or 300TB if large volume support has been enabled), and therefore the FlexGroup volume cannot be resized without adding additional member volumes.

Note

If you modify a FlexGroup volume to include more members, previously created snapshots are considered "partial" and are only available for access by clients from the .snapshot directory or the Previous Versions tab.

If a snapshot is considered "partial", it cannot be used in SnapRestore operations. However, partial snapshots can be used to restore individual files from .snapshot directories or the Previous Versions tab.

In releases earlier than ONTAP 9.3, do not expand FlexGroup volumes after a SnapMirror relationship is established. If you expand the source FlexGroup volume after breaking the SnapMirror relationship in releases earlier than ONTAP 9.3, you must perform a baseline transfer to the destination FlexGroup volume once again. Beginning with ONTAP 9.3, you can expand FlexGroup volumes that are in a SnapMirror relationship.

Steps

  1. Increase the size of the FlexGroup volume by increasing the capacity or performance of the FlexGroup volume, as required:

    If you want to increase the…​

    Then do this…​

    Capacity of the FlexGroup volume

    Resize all the member volumes of the FlexGroup volume:

    volume modify -vserver <svm_name> -volume <fg_name> -size <new_size>

    Performance to the FlexGroup volume

    Expand the FlexGroup volume by adding new member volumes (constituents):

    volume expand -vserver vserver_name -volume fg_name -aggr-list aggregate name,... [-aggr-list-multiplier constituents_per_aggr]

    The default value of the -aggr-list-multiplier parameter is 1.

    When expanding a FlexGroup volume using FabricPool, all local tiers (aggregates) must be attached to the same cloud tier.

Assuming existing aggregates (local tiers) or member volumes have not reached their maximum capacities (100/300TB or two billion files each), it is preferable to increase the overall size of the FlexGroup volume rather than adding additional member volumes.

Use volume expand only if increasing the existing volume size or file count is not an option or if the FlexGroup is being expanded across new hardware. The same number of member volumes should be added to all nodes in order to ensure consistent performance. For example, if an existing FlexGroup volume has 8 member volumes with four member volumes per node, adding two members per node will result in 12 member volumes, six member volumes per node.

When adding new members to new nodes, try to maintain a consistent number of member volumes per node as in the existing nodes. For example, if an existing FlexGroup volume has 8 member volumes with four member volumes per node, if the FlexGroup volumes is expanded to the new node, four member volumes should be added, resulting in a 12 member FlexGroup volume.

Adding new members to a FlexGroup volume changes the ingest heuristics to favor the new, empty, member volumes and can affect overall system performance for new data ingest until the new member volumes become balanced with pre-existing member volumes.

Examples

Example of increasing the capacity of the existing member volumes

The following example shows how to add 20 TB space to a FlexGroup volume volX:

cluster1::> volume modify -vserver svm1 -volume volX -size +20TB

If the FlexGroup volume has 16 member volumes, the space of each member volumes is increased by 1.25 TB.

Example of improving performance by adding new member volumes

The following example shows how to add four additional member volumes, two to each of the underlying local tiers (aggregates) to FlexGroup volume fg1:

cluster1::> volume expand -vserver svm1 -volume fg1 -aggr-list aggr1,aggr2 -aggr-list-multiplier 2

The size of the new member volumes is the same as that of the existing member volumes.

Increase the size of an individual volume

If you want to increase the size of an individual member volume in a FlexGroup volume, you can use the volume resize command.

Step

  1. Increase the size of a single FlexGroup member volume:

    volume size -volume <volume_name> -vserver <svm1> -new-size <new_size>

    The following example increases the size of FlexGroup member volume FG_0003 to 3.7GB:

    volume size -volume FG__0003 -vserver svm1 -new-size 3.7GB
vol size: Volume "svm1:FG__0003" size set to 3.70g.