Overview of Storage Availability

Applications of any type that read and write data to and from storage can suffer from two fundamental types of availability loss:

Loss of storage itself or access to the storage

Loss of the data residing on the storage

As with a typical storage deployment, you might consider data HA and redundancy as a mandatory requirement rather than an option. Applications accessing data are always expecting the data, and the storage that the data resides on, to be available at all times. If for some reason the storage is not available, then the application ceases to function.

Storage availability can be described as the requirement to protect against loss of access to stored data or loss of the storage in which the data resides. It is subtly different to that of data loss. In the case of data loss, whether due to accidental deletion, corruption, theft, or another event, it is a question of recovering the data from a snapshot, backup, or some other form of archive. Of course, in this case, if you can recover the lost data it implies that you previously had a process to copy data, either through snapshot, backup, replication, or another data management operation.

In general, the net effect of data loss or lack of storage availability is the same—loss of productivity. But the two types of data loss are distinct and addressed in different ways.

The subject of data availability in conjunction with the SteelFusion product family is documented in a number of white papers and other documents that describe the use of snapshot technology and data replication as well as backup and recovery tools.

To read the white papers, go to https://support.riverbed.com.

The following sections discuss how to make sure you have storage availability in both the Core and Storage Edge deployments.

Note: Core HA and Storage Edge HA are independent from each. You can have Core HA with no Storage Edge HA, and vice versa.