COMPAQ Software Product Description ___________________________________________________________________ PRODUCT NAME: HP RAID Software SPD 46.49.09 for OpenVMS, Version 2.6 DESCRIPTION HP RAID Software for OpenVMS is a software product that uses RAID tech- nology to manage groups of disk drives as arrays. The product supports RAID Level 0 arrays (Disk striping) for enhanced I/O performance and RAID Level 5 arrays (Disk striping with parity) for enhanced data avail- ability on both VAX and Alpha platforms. RAID Software also allows par- titioning or segmentation of a RAID array into multiple virtual de- vices. 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 2004 AE-Q1GDL-TE RAID Software virtual disks may not be used to boot the OpenVMS Op- erating System, nor may they serve as Open VMS 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 and Alpha proces- sors and OpenVMS cluster supported by OpenVMS. See the Software Re- quirements section for the qualified OpenVMS versions. RAID Software may be installed in an OpenVMS cluster configuration of any size sup- ported by OpenVMS Software, but the RAID Software has been qualified to run on a maximum of 20 nodes within a single OpenVMS cluster con- figuration. 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, includ- ing 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___________________________________ Disk_Space_________VAX-based__________Alpha-based__________________ During instal- 3500 blocks 5000 blocks (2.44 megabytes) lation (1.70 megabytes) For permanent 2500 blocks 4000 blocks (1.85 megabytes) use________________(1.22_megabytes)________________________________ SOFTWARE REQUIREMENTS RAID Software requires the OpenVMS VAX Operating System (Version 6.2, 7.2 and 7.3) or OpenVMS Alpha (Versions 6.2, 7.2-2, 7.3, 7.3-1 and V7.3- 2) as a prerequisite. No other prerequisite software is required. RAID Software Version V2.6 will be the last version to support Open- VMS versions V6.2. Mixed-architecture VMScluster systems (i.e. containing both VAX and Alpha 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 HP OpenVMS Cluster Software Software Prod- uct Description (SPD 29.78.xx). On OpenVMS 7.2-2 and 7.3, 7.3-1 and 7.3-2 the following restriction applies: SYSGEN Parameter MSCP_SERVE_ALL bit 3 must be set to prevent the serv- ing of Host Based RAID sets to other members of the cluster. Bit 3 en- ables the pre-V7.2 behavior of not serving RAID sets to other clus- ter members. See the Release Notes for more details. 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 This layered product is only available as part of the OpenVMS Consol- idated Software Distribution on CD-ROM for VAX (QA-VWJ8A-A8) and on the HP CD-ROM Software Library for OpenVMS Alpha (QA-03XAA-H8). ORDERING INFORMATION Three licensing options are available: RAID Array Access License: VAX: QL-0MHA*-AA Alpha: QL-2YFA*-AA This license option provides the purchaser with the right to use the RAID Software for OpenVMS on a single VAX or Alpha system to create and use up to the supported number (50) of RAID arrays. One RAID Ar- ray Access License is required for each VAX or Alpha system in an Open- VMS cluster on which RAID Software for OpenVMS is to execute. Storage Concurrent Use License: QL-0MGAA-3B 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 or Alpha system. 7 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. Documentation: VAX: QA-0MGAA-GZ Alpha: QA-0MGAA-GZ Software Product Services: Array Access (VAX): QT-0MHA*-** Array Access (Alpha): QT-2YFA*-** Storage: QT-0MGA*-** 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 software product service options are available from HP. For more information, contact your local HP office. SOFTWARE WARRANTY Warranty for this software product is provided by HP with the purchase of a license for the products as defined in the Software Warranty Ad- dendum to this SPD. The previous information is valid at time of release. Please contact your local HP office for the most up-to-date information. 2004 Hewlett-Packard Development Company, L.P. 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. Proprietary 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. HP, the HP logo, VAX and VMS Registered in U.S. Patent and trademark Office. OpenVMS and Tru64 are trademarks of HP Information Technolo- gies Group, L.P. in the United States and other countries. © 2004 Hewlett-Packard Development Company, L.P. All Rights Reserved. 9