Dell EMC Metro node 7.1 Administrator Guide

• Storage volumes are provisioned from storage arrays that are supported by metro node as thin-capable (where the thin properties are shown). The storage volumes must also be from a storage-array family that metro node supports (Dell EMC PowerStore, Dell EMC UnityXT). The value corresponding to the storage-array-family property must be XTREMIO, CLARiiON, or SYMMETRIX and it must not be other or -.
• Storage volume display thin properties.
• All the mirrors are created from the same storage-array family that metro node supports (For a RAID-1 configuration). The value corresponding to the storage-array-family property must not be mixed, other or -. In the following scenarios, the thin capable attribute can show false even if the mirrors are created from the same storage-array family that metro node supports:
  • The array software does not support the UNMAP feature.
  • The UNMAP feature is not turned on the arrays.

Creating thin-enabled virtual volumes through the legacy provisioning method

In the legacy method, you can create a thin-enabled virtual volume in these two ways:

• EZ Provisioning: Use the storage-tool compose --thin command to create a virtual-volume on top of the specified storage-volumes, building all intermediate extents, local, and distributed devices as necessary.
• Advanced provisioning: Perform these tasks:
  • Manually claiming thin storage volumes that are discovered by metro node.
  • Creating extents on top of the thin-capable storage volume using the extent create command.
  • Creating thin-capable local devices using the local-device create command.
  • Creating thin-enabled virtual volumes using the virtual-volume create --thin command.
    NOTE:

    • If you create a virtual volume without the --thin attribute, a thick volume is created by default. The virtual volume must be built on top of a RAID 1 device.
    • Slicing of storage-volumes and extents is not allowed, that is no "slicing at the top" and no "slicing at the bottom" in metro node. All devices should be mapped directly back to a single storage volume or 1:1 mapping.

Use the following commands to list thin-capable virtual volumes, or to set virtual volumes as thin-enabled:

For example, to set all virtual volumes at cluster-1 to thin-enabled, type the following command:

virtual-volume set-thin-enabled true --virtual-volumes /clusters/cluster-1/virtual-volumes/*

The CLI Guide for metro node provides more information about the commands and their usage.