Dell EMC Metro node 7.0.1 Online Help

About devices

Devices combine extents or other devices into one large device with specific RAID techniques such as mirroring or striping. Devices can only be created from extents or other devices. A device's storage capacity is not available until you create a virtual volume on the device and export that virtual volume to a host.  You can create only one virtual volume per device. Creating a virtual volume on a device indicates the device configuration is complete.

Note that devices use storage from one cluster only. To create a device from storage in both clusters in a metro node Metro, refer to Creating distributed devices.

There are two ways to create devices:

• Simple — a device configured by using one component (an extent).
• Complex — a device that has more than one component, combined by using a specific RAID type. The components can be extents or other devices (both simple and complex).

To create a device using different device types, use the CLI. The CLI Guide for metro node provides more information.