## 6.1.7 Volumes for various topologies 

A Basic  volume is the simplest form of volume. It consists of a single volume copy, which is made up of extents that are striped  across all MDisks in a storage pool. It services I/O by using readwrite cache and is classified as fully allocated (reported real capacity and virtual capacity are equal). You can create other forms of volumes, depending on the type of topology that is configured on your system: 

GLYPH<SM590000> With standard topology, which is a single-site configuration, you can create a basic volume or a mirrored volume. 

By using volume mirroring, a volume can have two physical copies. Each volume copy can belong to a different pool, and each copy has the same virtual capacity as the volume. In the management GUI, an asterisk indicates the primary copy of the mirrored volume. The primary copy indicates the preferred volume for read requests. 

GLYPH<SM590000> With HyperSwap topology, which is a three-site HA configuration, you can create a basic volume or a HyperSwap volume. 

HyperSwap volumes create copies on separate sites for systems that are configured with HyperSwap topology. Data that is written to a HyperSwap volume is automatically sent to both copies so that either site can provide access to the volume if the other site becomes unavailable. 

Note:  For IBM Storwize V5000 Gen2, the HyperSwap topology is supported on Storwize V5030 and Storwize V5030F systems only. 

GLYPH<SM590000> The IBM Spectrum Virtualize V7.6.0 release also introduces Virtual Volumes  (VVols). These volumes are available in a system configuration that supports VMware vSphere Virtual Volumes. These volumes allow VMware vCenter to manage system objects, such as volumes and pools. The Spectrum Virtualize system administrators can create volume objects of this class, and assign ownership to VMware administrators to simplify management. 

For more information about configuring vVol with IBM Spectrum Virtualize, see Configuring VMware Virtual Volumes for Systems Powered by IBM Spectrum Virtualize , SG24-8328. 

Note:  From V7.4.0 onwards, it is possible to prevent accidental deletion of volumes, if they recently performed any I/O operations. This feature is called Volume protection , and it prevents active volumes or host mappings from being deleted inadvertently. This is done by using a global system setting. For more information, see IBM Knowledge Center. 

