The VMAX Adapter enables you to use ESI to expand and extend existing LUNs into metas and create new metas or meta volumes for a VMAX host or cluster. Metas are combined storage devices that are grouped together to create a larger meta.
Metas represent meta volumes, composite LUNs, metadevices, meta LUNs, composite volumes, and metaheads. Meta members represent meta volume members, constituent LUNs, and composite LUN members.
To create and manage metas, use the ESI PowerShell Toolkit meta cmdlets.
ESI has the following limitations for expanding LUNs into metas and for creating and managing metas:
Expanding a bound stripe meta volume results in the creation of a Business Continuity Volume (BCV), which has the same meta configuration to preserve data. During the expansion, the system creates a mirror relationship between the meta and the BCV, which means the meta and the BCV contain the same data. After the expansion, the storage system detaches the BCV from the meta and by default, ESI does not delete the device. You can manually delete the devices with EMC tools, such as EMC Solutions Enabler SYMCLI or Unisphere for VMAX, to manage disk space.
The Expand-EmcLun cmdlet does not work for thin single hyper volumes or LUNs (bound and unbound). The command only works with existing VMAX meta volumes.
You cannot expand meta volumes that involve a clone, remote data facility (RDF), or snap session. However, you can expand existing bound or unbound LUNs by forming new metas with the New-EmcCompositeLun cmdlet.
You cannot compress or shrink meta volumes.