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Enabling space allocation for thinly provisioned LUNs

If you set the space-allocation option to enabled, Data ONTAP notifies the host when the volume has run out of space and the LUN in the volume cannot accept writes. Also this option enables Data ONTAP to reclaim space automatically when your host deletes data. The space-allocation option is set to disabled by default.

About this task

The space allocation functionality uses the Logical Block Provisioning feature as defined in the SCSI SBC-3 standard.

Steps

  1. Use the lun modify command to take the LUN offline.

    Example

    lun modify -vserver vs1 -volume vol2 -lun lun1 -state offline

  2. Use the lun modify command to set the -space-allocation parameter to enabled.

    Example

    lun modify -vserver vs1 -volume vol2 -lun lun1 -space-allocation enabled

  3. Use the lun show command to verify that you enabled space allocation.

    Example

    lun show -vserver vs1 -volume vol2 -lun lun1 -fields space-allocation
    vserver path           space-allocation
    ------- -------------- ----------------
    vs1     /vol/vol2/lun1 enabled

  4. Use the lun modify command to bring the LUN back online.

    Example

    lun modify -vserver vs1 -volume vol2 -lun lun1 -state online

  5. On the host, rescan all disks to ensure that the change to the -space-allocation option is correctly discovered.

After you finish

You must actively monitor your volume and aggregate to ensure enough space is available for your LUNs.