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Distributed devices
About distributed devices
Distributed devices are configured by using storage from both clusters, and are used only in a metro node Metro system. A
distributed device's components must be other devices, and those devices must be created from storage in both clusters. You
can also create a distributed device by mirroring a device remotely.
Devices can be components of other devices. If a device is not a component of another device, it is referred to as a top-level
device. Distributed devices can be created only from top-level devices.
To create a distributed device, a Logging volume must exist in the system. Logging volumes are used to keep track of blocks
written during an inter-cluster link failure or when one leg of a distributed RAID-1 becomes unreachable and then recovers. After
a link failure is restored or an unreachable leg recovers, metro node uses the information in logging volumes to synchronize the
mirrors by sending only changed blocks across the link.
Figure 4. Distributed device configurations
The Distributed Devices view
The Distributed Devices view shows all distributed devices in the system. Use this view to quickly see the status of a
distributed device, the components of a distributed device, or search for a distributed device. By default, distributed devices are
sorted ascending alphabetical order. The arrow in the default sort column indicates the direction of the sort; ascending (
) or
descending ( ). You can sort columns of data, select one or more objects in the list, and show/hide properties on the screen.
This view shows the following information about distributed devices. To see additional properties, click the distributed device
name link to open the properties dialog box.
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Provisioning storage