Software Product Description ___________________________________________________________________ PRODUCT NAME: POLYCENTER Striping for OpenVMS VAX, Version 2.1 SPD 31.66.02 DESCRIPTION POLYCENTER Striping implements disk striping for the OpenVMS Operat- ing System. The product provides the ability for users to create one or more stripesets, each comprised of two or more physical disk drives and represented to the user application (and operating system) as a single pseudo-device. Stripesets must be composed of disks of a sin- gle type. Disk striping interleaves multiple disks to improve I/O performance in the same way that high-performance memory systems interleave mem- ory banks. In each case, data requests are decomposed and distributed to physical storage components that process those requests in paral- lel. There are three types of I/O performance problems that disk striping can help relieve. They are: 1. Applications that require very high data transfer rates 2. Systems in which static disk load balancing is ineffective 3. Applications that are prohibited from distributing data across mul- tiple disks but need higher throughput than is available from a sin- gle disk The pseudo-device responds to all of the I/O operations defined for ordinary disk drives including physical, logical, and virtual I/O. As a result, the striping driver is transparent to all OpenVMS software other than diagnostics. However, a stripeset may not be an OpenVMS boot or dump device, and BACKUPs must be done on the pseudo-device, not on the member units. DIGITAL August 1993 AE-NZ29C-TE POLYCENTER Striping does not support MSCP serving of Stripesets to other nodes in a VMScluster. POLYCENTER Striping is not supported on Open- VMS AXP. A Digital Command Language (DCL) interface (CLI) is provided that en- ables the privileged user to define stripesets and to create and de- stroy the pseudo-devices that represent them. It also allows statis- tics and configuration information associated with the pseudo-devices to be listed. HARDWARE REQUIREMENTS VAX, MicroVAX, VAXstation, or VAXserver configuration as specified in the System Support Addendum (SSA 31.66.02-x). SOFTWARE REQUIREMENTS For Systems Using Terminals (No DECwindows Interface): OpenVMS Operating System Refer to the System Support Addendum (SSA 31.66.02-x) for availabil- ity and required versions of prerequisite software. ORDERING INFORMATION Software Licenses: QL-YELA9-J* Software Update License: QL-YELA9-S* Software Media: QA-YELA9-H* Software Documentation: QA-YELAA-GZ Software Product Services: QT-YELA9-L* * Denotes variant field. For additional information on available li- censes, services, and media, refer to the appropriate price book. 2 SOFTWARE LICENSING This software is furnished under the licensing provisions of Digital Equipment Corporation's Standard Terms and Conditions. For more in- formation about Digital's licensing terms and policies, contact your local Digital office. LICENSE MANAGEMENT FACILITY SUPPORT This layered product supports the OpenVMS License Management Facil- ity. License units for this product are allocated on a CPU-capacity basis. Each node that requires acccess to a stripeset requires a license for POLYCENTER Striping. For more information on the License Management Facility, refer to the OpenVMS Operating System Software Product Description (SPD 25.01.xx) or the License Management Facility manual of the OpenVMS Operating Sys- tem documentation set. For more information about Digital's licensing terms and policies, con- tact your local Digital office. SOFTWARE PRODUCT SERVICES A variety of service options are available from Digital. For more in- formation, contact your local Digital office. SOFTWARE WARRANTY Warranty for this software product is provided by Digital with the pur- chase of a license for the product as defined in the Software Warranty Addendum of this SPD. 3 [TM] The DIGITAL Logo, DECwindows, MicroVAX, POLYCENTER, VAX, VAX- cluster, VAXserver, VAXstation, VMS, and OpenVMS are trade- marks of Digital Equipment Corporation. 4