HP Software Product Description ___________________________________________________________________ PRODUCT NAME: HP RAID Software SPD 46.49.10 for OpenVMS, Version 3.0 DESCRIPTION HP RAID Software for OpenVMS is a layered software product that uses RAID technology to manage groups of disk drives as arrays. The prod- uct supports RAID Level 0 arrays (Disk striping) for enhanced I/O per- formance and RAID Level 5 arrays (Disk striping with parity) for en- hanced data availability on VAX, Alpha, and I64 platforms. RAID Soft- ware also allows partitioning or segmentation of a RAID array into mul- tiple virtual devices. RAID Software for OpenVMS Capabilities and Features RAID Software manages groups of between 1 and 32 physical disks (be- tween 3 and 32 for RAID Level 5) as arrays. Applications use a vir- tual disk as if it were a physical disk. A maximum of 50 such arrays per OpenVMS cluster are supported, in any mixture of RAID Level 0 and RAID Level 5. RAID virtual disks may be accessed directly from any member of a Open- VMS cluster for which a valid license is in effect. (All VMScluster systems may access virtual disks created using the Storage Concurrent Use license QL-0MGAA-3B.) Virtual disks may not be MSCP served. The disks in a RAID level 5 array may be of different types, although disks of a single type are recommended for consistent performance and optimal use of storage capacity. January 2005 RAID Software virtual disks may not be used to boot the OpenVMS Op- erating System, nor may they serve as OpenVMS cluster quorum disks. They may, however, contain OpenVMS page and swap files. RAID Software may be used in conjunction with OpenVMS Volume Shadow- ing. OpenVMS shadow sets may be used as RAID array members for RAID Level 0 arrays to form RAID Level 0+1 arrays. However, virtual disks may not be members of OpenVMS shadow sets. A RAID Level 0 array whose members are shadow sets is a high perfor- mance, high data availability storage solution for most applications. RAID array members can be spread across controllers. Partitioning is the process of dividing a RAID array into one or more RAID virtual devices. The RAID Software allows you to specify how many partitions are to be used in a given RAID array and how large each par- tition should be. One or more partitions can be created on a single- member RAID Level 0 array or multiple-member RAID Level 0 or RAID Level 5 arrays. The maximum number of partitions for any array is 64. The maximum size of one array is 1 TB. Features Applicable to RAID Level 0 Arrays The usable capacity of RAID Level 0 array is approximately given by: Usable Capacity = N * 0.99 * CS Where N is the number of physical disks in the array. CS is the storage capacity of the smallest disk in the array. The purpose of RAID Level 0 technology is to provide I/O intensive ap- plications with greater I/O performance from a given I/O hardware con- figuration than would normally be achieved by using the disks as in- dividual volumes. This is also referred to as Disk Striping. Depend- ing on the application, enhanced I/O performance may be delivered as: o more I/O requests serviced per unit time due to probabilistic load balancing, or o higher data transfer rate due to concurrent transfer of data to or from more than one disk to satisfy a single request. 2 Features Applicable to RAID Level 5 Arrays The usable capacity of RAID Level 5 array is approximately given by: Usable Capacity = (N-1) * 0.99 * CS Where N is the number of physical disks in the array. CS is the capacity of the smallest disk in the array. RAID Software protects against loss of data and loss of data acces- sibility due to the failure of any single disk in a RAID Level 5 ar- ray. If a disk in a RAID Level 5 array fails, RAID Software provides continued service to applications by regenerating the failed disk's data using information from the array's remaining disks. (For full pro- tection against loss of data availability due to single hardware fail- ures, RAID Software can be used in conjunction with redundant hard- ware and supporting software throughout the system.) While a RAID Level 5 array is reduced by a failed disk, data can be read and written, but no redundancy is provided. A second disk fail- ure while an array is reduced prevents application access to the data stored on the array, and may result in data loss. RAID Software reconstructs the contents of a failed disk if a replace- ment disk is assigned to it. Reconstruction does not interrupt appli- cation access to data on the array, although performance may be af- fected. Replacement disks may either be assigned to RAID Software by the storage administrator (using a DCL command) or they may be placed in a spareset associated with one or more RAID Level 5 arrays. If a disk in a RAID Level 5 array with an associated spareset fails, RAID Software automatically acquires a replacement disk from the spareset and performs reconstruction without storage administrator interven- tion. Using RAID Software for OpenVMS 3 To use RAID Software for OpenVMS, the storage administrator first cre- ates an array using DCL functions supplied with the software. This de- stroys any data previously stored on the disks and creates the data structures required to manage the array. The member disks of a RAID Software array are ODS-2 structured volumes, so OpenVMS mechanisms pro- tect against inadvertent misuse of members for the life of the array. However, the virtual disk units created by RAID Software can be ini- tialized as FILES-11 ODS2 or ODS5 or any other volume structure. Each virtual disk created by RAID Software is a single management en- tity. The storage administrator should use appropriate storage man- agement procedures (such as backups) with virtual disks, which can be considerably larger than typical physical disks. Once a collection of physical disks is bound into an array, it is not possible to retrieve data directly from the array's individual member disks. Performance of RAID Software for OpenVMS The primary purpose of RAID for OpenVMS RAID Level 0 arrays is to en- hance application performance by improving I/O request processing and /or data transfer rate. RAID Level 0 technology normally implies a re- duction in data reliability. The storage administrator can improve data reliability by increasing backup frequency or using RAID Software in conjunction with Volume Shadowing for OpenVMS. The primary purpose of RAID Software Level 5 arrays is to improve data reliability. It may provide the secondary benefit of improved perfor- mance (due to load balancing) for applications whose I/O workload con- sists largely of reading data. For applications with mostly write I/O workloads, RAID Software Level 5 arrays may provide lower I/O perfor- mance than conventional disks because it must update redundant infor- mation each time an application writes data. The storage administrator should understand application I/O charac- teristics and weigh the relative priorities of performance, equipment cost, and data reliability to determine whether RAID Software is ap- propriate for use with a given application. 4 HARDWARE REQUIREMENTS RAID Software is supported when used with the VAX, Alpha, and I64 pro- cessors and supported OpenVMS cluster configurations. See the Soft- ware Requirements section for the qualified OpenVMS versions. RAID Soft- ware may be installed in an OpenVMS cluster configuration of any size supported by OpenVMS Software, but the RAID Software has been qual- ified to run on a maximum of 20 nodes within a single OpenVMS clus- ter configuration. RAID Software requires a minimum of 1 (for RAID Level 0) or 3 (for RAID Level 5) and a maximum of 32 physical disks for each array. Up to 50 arrays may be created in a single OpenVMS cluster. Disks, storage el- ements, (and the subsystem configurations that contain them) are sup- ported by the OpenVMS Operating System Versions (see Software Require- ments) through the following device drivers shown in Table 1. ___________________________________________________________________ Table_1:_Supporting_Device_Drivers_________________________________ Device Drivers___Description______________________________________________ DUDRIVER For Digital Storage Architecture (DSA) disks, including MSCP-served Disks. DKDRIVER For SCSI disks DRDRIVER For StorageWorks RAID Array 200 series controllers, also known as SWXCR DKQDRIVER_For_HGx_connected_disks__________________________________ 5 ___________________________________________________________________ Table_2:_Disk_Space_Requirements___________________________________ Alpha- Disk_Space__I64-based____based________VAX-based____________________ During in- 10,000 6,000 5,000 blocks stallation blocks blocks For per- 8,000 4,000 3,000 blocks manent blocks blocks use________________________________________________________________ SOFTWARE REQUIREMENTS OpenVMS VAX: V7.3 (SPD 25.01.XX) OpenVMS Alpha: V7.3-2 (SPD 25.01.XX) V8.2 (SPD 82.35.XX) OpenVMS I64: V8.2 (SPD 82.35.XX) Refer to the appropriate OpenVMS Operating System Software Product De- scription (SPD) for additional details. RAID Software Version 3.0 will be the last version to support Open- VMS VAX. RAID Software Version 2.6 supports the prior versions of Open- VMS per SPD 46.49.09. Mixed-architecture VMScluster systems (i.e. containing VAX, Alpha and I64 systems) are supported as long as all VMScluster members are run- ning compatible versions of the OpenVMS operating system qualified by RAID Software. For a chart of the compatible versions of the operat- ing systems, refer to the VAXcluster Software for OpenVMS VAX Soft- ware Product Description (SPD 29.78.XX) and the VMScluster Software for OpenVMS Alpha and OpenVMS I64 Software Product Description (SPD 42.18.XX). In order to bind RAID arrays, all physical disks that comprise the RAID arrays must be accessible, (local or MSCP served), on all nodes in an OpenVMS cluster having the RAID software running. 6 If RAID Level 0 arrays with OpenVMS shadow sets as members are required, a valid OpenVMS Volume Shadowing license must be in effect on every OpenVMS cluster node running the RAID Software. Shadow sets may not be used as members of RAID Level 5 arrays. DISTRIBUTION MEDIA HP RAID Software for OpenVMS VAX product is available on the OpenVMS Consolidated Software Distribution (QA-VWJ8A-A8). The package includes media and documentation on CD-ROM. HP RAID Software for OpenVMS Alpha product is available on the Open- VMS Alpha Software Products Library (QA-03XAA-H8). The Products Li- brary includes media and documentation on CD-ROM. HP RAID Software for OpenVMS I64 product is available on the layered products media within the Operating Environment package. The layered products media includes the product binaries and on-line documenta- tion. ORDERING INFORMATION Three licensing options are available: RAID Array Access License: VAX: QL-0MHA*-AA Alpha: QL-2YFA*-AA I64: BA383AC This license option provides the purchaser with the right to use the RAID Software for OpenVMS on a single VAX, Alpha, or I64 system to cre- ate and use up to the supported number (50) of RAID arrays. One RAID Array Access License is required for each VAX, Alpha, or I64 system in an OpenVMS cluster on which RAID Software for OpenVMS is to exe- cute. Storage Concurrent Use License: QL-0MGAA-3B 7 This license option provides the purchaser with the right to include a single disk, storage element, or shadow set in an array. One Stor- age Concurrent Use License is required for each disk, storage element, or shadow set to be included in a RAID Software for OpenVMS array. Once an array is created, it may be accessed by any OpenVMS cluster VAX, Alpha, or I64 system. For purposes of the Storage Concurrent Use License, the measure of use is equal to a single disk, storage element, or shadow set to be in- cluded in an array, no matter how many OpenVMS cluster CPUs have ac- cess to that array. Each shadow set used as a member of a RAID Level 0 array requires a single Concurrent Use License, regardless of the number of physical disks in the shadow set. Disks, storage elements, and shadow sets that are members of spare- sets do not require Storage Concurrent Use Licenses. SOFTWARE LICENSING This software is furnished only under a license. For more information about HP licensing terms and conditions, contact your local HP office. License Management Facility Support RAID Software for OpenVMS software uses the OpenVMS License Manage- ment Facility. License Units for the RAID Software for OpenVMS RAID Array Access Li- cense are allocated on a CPU-capacity basis. License Units for the RAID Software for OpenVMS Storage Concurrent Use License are independent of CPU capacity. One Storage Concurrent Use License is required for each disk, storage element, or shadow set in- cluded in an array, no matter how many VMScluster CPUs have access to the array. 8 For more information on the License Management Facility, refer to the OpenVMS Operating System Software Product Description (SPD 25.01.xx) or the OpenVMS Operating System documentation. SOFTWARE PRODUCT SERVICES A variety of service options are available from HP. For more infor- mation, contact your local HP account representative or distributor. Information is also available on www.hp.com/hps/software. SOFTWARE WARRANTY This software is provided by HP with a ninety-day conformance warranty in accordance with the HP warranty terms applicable to the license pur- chase. © Copyright 2005 Hewlett-Packard Development Company, L.P. Confidential computer software. Valid license from HP required for pos- session, use or copying. Consistent with FAR 12.211 and 12.212, Com- mercial Computer Software, Computer Software Documentation, and Tech- nical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional war- ranty. HP shall not be liable for technical or editorial errors or omis- sions contained herein. 9