5 Replicating storage

Replication is an industry-standard term for making copies or backing up data. With HP P6000/EVA storage systems, entire virtual disks can be replicated locally or remotely using a variety of methods:

HP P6000 Business Copy (local replication). Make local copies of virtual disks using snapclones, snapshots, mirrorclones and preallocated containers. Replicated virtual disks are located on the same storage system as the source.

HP P6000 Continuous Access (remote replication). Make remote copies of virtual disks. Replicated virtual disks are located on a different storage system than the source, typically at a geographically separate site.

This chapter focuses on using the local replication features in HP P6000 Command View. For information on using the remote replication features in HP P6000 Command View, see the HP P6000 Continuous Access Implementation Guide.

HP P6000 Business Copy software

HP P6000 Business Copy software is a licensed feature of HP P6000/EVA storage systems that enables you to:

Create point-in-time copies, called snapshots and snapclones, and ongoing copies called mirrorclones of virtual disks

Specify snapshot, snapclone, and mirrorclone properties, such as redundancy (Vraid) level, read cache, and write protection.

Present snapshots, snapclones, and mirrorclones as disks to hosts

Allow host I/O to snapshots and snapclones

Instantly restore the content of a virtual disk from snapshots or mirrorclones or from snapshots of mirrorclones

HP recommends that you unmount the target virtual disk before restoring the data. This ensures that the host server cache is flushed.

Perform virtual disk online migration, which allows you to change the Vraid of the virtual disk, move a virtual disk from one disk group to another, or do both in a single action without impacting host I/O.

Features vary based on the array controller software version. For specific supported features and maximums, see HP P6000 Enterprise Virtual Array Compatibility Reference. Specialized replication user interfaces, such as HP P6000 Replication Solutions Manager, offer additional features.

Snapclones

A snapclone is an independent point-in-time copy of a virtual disk. It is independent because all of the data from the source virtual disk is copied to the snapclone. Use snapclones when you need independent and durable copies; for example, for data mining, data warehousing, or preproduction testing.

Follow these guidelines for the use of snapclones:

The array must have a local replication license.

A snapclone can be in a different disk group than the source.

The redundancy (Vraid) level of a snapclone can be any level relative to the source.

Until a snapclone is normalized, another snapclone of the same source cannot be created.

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HP manual Replicating storage, HP P6000 Business Copy software, Snapclones