Administering Volumes

Administer volumes on HPE Ezmeral Data Fabric.

HPE Ezmeral Data Fabric provides volumes as a way to organize data and manage fabric performance.

A volume is a logical storage unit that allows you to apply policies to a set of files, directories, and sub-volumes. You can use volumes to enforce disk usage limits, establish ownership and accountability, and measure the cost generated by different projects or departments. For example, you could create a volume for each user, department, or project.

A volume consumes storage space only when data is written to the volume.

Volume Types

Volumes can be of the following types.

• Standard volume: A initial or original volume that contains data.
• Mirror volume: A replica of a standard volume that replicates the data present on a standard volume.

Volume Data Backup

Following are the ways in which data on volumes can be backed up for restoration purpose.

• Creating mirrors or mirror volumes: Data in a volume is replicated when you create mirror volumes. A volume that is mirrored is called a standard volume. The mirrored version of a volume is called a mirror volume. You can create mirrors of mirror volumes to replicate the data present on mirror volumes. Such volumes are called cascading mirrors.
• Creating volume snapshots: The state of data in a volume is recorded at the point-in-time of the volume snapshot creation. A snapshot is a read-only image of a volume at a specific point in time. Snapshots are useful any time you need to be able to roll back to a known good data set at a specific point in time. For example, before performing a risky operation on a volume, you can create a snapshot to enable rollback capability for the entire volume.

  A snapshot takes no time to create, and initially uses no disk space, because it stores only the incremental changes needed to roll the volume back to the state at the time the snapshot was created. The storage used by a volume's snapshots does not count against the volume's quota.

  Security policies can be applied to volumes to control access to the volume data. See Administering Security Policies for more information.