Home > APEX > Storage > White Papers > Dell APEX Block Storage for AWS > Data mobility
There are a couple of options to address data mobility with APEX Block Storage. The product provides native replication and snapshot shipping. With native replication you can asynchronously transfer data between APEX Block Storage systems. With snapshot shipping, the product can transfer entire volumes. This process will only be available and orchestrated with the APEX Navigator
APEX Block Storage enables you to create instantaneous copies of volumes, that is, snapshots. A snapshot can be manipulated as any volume exposed by the storage system. Snapshots taken at the same time form a consistency group can be manipulated as a group.
The APEX Block Storage system enables you to take snapshots of existing volumes, up to 128 per volume. The snapshots are thin provisioned and are extremely quick to create. When a snapshot is generated, it becomes a new, unmapped volume in the system. You can manipulate it in the same manner as any other volume exposed by the APEX Block Storage system.
The structure related to all snapshots that result from one volume is referred to as a V-Tree. When taking a snapshot in the system, you can specify more than one volume. They are consistent in the sense that they were all taken at the same time. If there is a contextual relationship between the data contained by all the snapshot members, then that set is meaningful. The consistency group allows manipulation of the entire set.
If you remove an entire consistency group, all the snapshots that were taken together are removed.
Snapshot policies enable you to define policies where you can configure the number of snapshots to take at a given time for one or more volumes.
Snapshots are taken according to the rules defined. You can define the time interval in-between two rounds of snapshots as well as the number of snapshots to retain, in a multi-level structure. For example, take snapshots every x minutes/hours/days/weeks. There are one to six levels; the first level has the most frequent snapshots.
Snapshots can be created with a “Secure Snapshot” option. These snapshots are protected until the expiration time is reached. During this time, these rules apply:
A V-Tree consists of the root volume and all its descendant volumes and snapshots.
A V-Tree is the structure that consists of a volume and the snapshots resulting from that volume. It is a tree that spans from the source volume at its root, whose descendants are either snapshots of the volume itself or snapshots of a snapshot. In Figure 12, S111 and S112 are snapshots of V1. S121 is a snapshot of snapshot S111. Together, V1 and S1xy are the V-Tree of V1.