The thin provisioning function permits the capacity of storage systems to be used efficiently. Devices (LUNs) with preconfigured virtual capacity are offered to the application, while internally the storage system provides the necessary physical capacity. SHC-OSD supports thin provisioning for the storage systems ETERNUS DX/AF and for Symmetrix/VMAX3.
When storage space is provided for a new application, the administrators must take into account both the current and the future capacity requirements of the application. Users as a rule assign an application far more physical storage than is actually required for a particular period in order to reduce the risks of capacity bottlenecks, interruptions of the application, and effort involved in providing additional storage. This assigned but unused storage causes costs both when it is procured and when it is operated.
However, even with careful planning it is, on the other hand, repeatedly necessary to provide additional storage for an application. This generally entails a temporary failure of the application.
Thin provisioning solves these problems by avoiding unused, cost-intensive storage. It is based on the option of configuring and making accessible a virtual volume with high capacity for a server or an application. This virtual volume occupies physical storage from a jointly used storage pool as required. Sufficient capacity for the applications is provided in this storage pool. The capacity can be changed dynamically.
Implementation of thin provisioning depends on the storage system.
Commands for thin provisioning
Command | Function |
Sets limit values for thin provisioning (Symmetrix/VMAX3) | |
Displays limit values for thin provisioning (Symmetrix/VMAX3) | |
Displays the configuration of the TPPs (ETERNUS DX/AF) | |
Displays device information of the TPVs (ETERNUS DX/AF) | |
Displays the configuration of the thin pools (Symmetrix/VMAX3) | |
Displays device information of the thin devices and data devices (Symmetrix/VMAX3) |