Computer Associates BrightStor CA-Vtape Virtual Tape System Software

Transcription

1 Edward E. Cowger, Herb Gepner Product Report 8 October 2002 Historical Computer Associates BrightStor CA-Vtape Virtual Tape System Software Summary Computer Associates (CA s) BrightStor CA-Vtape Virtual Tape System is software-based and avoids vendor lockin as it addresses tape bottlenecks by intercepting tape requests and writing the data to DASD. Note BrightStor CA-Vtape was acquired by CA from Sterling Software (originally called SAMS:Vtape) to supplement CA s media management group of products. This product can allow users to utilize their established tape and mainframe hardware to implement a virtual tape system. Because BrightStor CA- Vtape is a software-based solution, it easily scales to meet the user s needs without additional hardware costs. BrightStor CA-Vtape can be installed on all supported releases of z/os and OS/390 with the JES 2 job entry subsystem. It is highly touted by CA as providing unique high availability for e-business data. Table of Contents Overview Analysis Pricing Competitors Strengths Limitations Insight List Of Tables Table 1: Overview: Computer Associates BrightStor CA-Vtape Virtual Tape System Table 2: Features and Functions: Computer Associates BrightStor CA-Vtape Virtual Tape System Gartner Reproduction of this publication in any form without prior written permission is forbidden. The information contained herein has been obtained from sources believed to be reliable. Gartner disclaims all warranties as to the accuracy, completeness or adequacy of such information. Gartner shall have no liability for errors, omissions or inadequacies in the information contained herein or for interpretations thereof. The reader assumes sole responsibility for the selection of these materials to achieve its intended results. The opinions expressed herein are subject to change without notice.

2 Corporate Headquarters Computer Associates Intl., Inc. One Computer Associates Plaza Islandia, NY 11749, U.S.A. Tel: ; Fax: Internet: Overview Table 1: Overview: Computer Associates BrightStor CA-Vtape Virtual Tape System Product Name Product Type Platform Supported Current Release Levels Current Installed Base Price Range BrightStor CA-Vtape Virtual Tape System Virtual tape system All supported releases of z/os and OS/390 utilizing JES2 Version 2.0 Gartner estimates that there are several hundred user installations. BrightStor CA-Vtape pricing begins at US$4,300, which includes support for one virtual tape device. Table 2: Features and Functions: Computer Associates BrightStor CA-Vtape Virtual Tape System Base-System Facilities Base Requirements Architecture Virtual Tape Devices Managing Virtual Volumes Uses established tape and hardware to implement virtual tape with the mainframe. As tape-storage needs grow, BrightStor CA-Vtape grows with these needs without compromising the choice of hardware. BrightStor CA-Vtape runs as a STC or started task. It is composed of virtual devices, virtual volumes, dataspaces, datasets and the disk buffer pool. The backstore engine runs in a separate address space. Through the main menu and Interactive System Productivity Facility (ISPF) interface, the user can drill down to manage BrightStor CA-Vtape objects. BrightStor CA-Vtape emulates the microcode that controls and 3490-type tape drives. OS/390 acts as if the device actually exists. Applications read from and write to these devices exactly as they would interface with a real unit. A maximum of 512 virtual devices and a maximum of 500,000 virtual volumes can be supported. Any tape management system will manage virtual volumes exactly like a physical tape. The user defines the volume range to the tape management system and to BrightStor CA-Vtape during installation. BrightStor CA-Vtape will synchronize scratch volumes with the tape management system as well as verify the volume status and ownership. Virtual volumes may reside either in the disk buffer pool or on a physical tape stacked with other virtual volumes or both. 8 October

3 Table 2: Features and Functions: Computer Associates BrightStor CA-Vtape Virtual Tape System Base-System Facilities Disk Buffer Pool A disk buffer pool in a direct access storage device (DASD) is used to contain data before and after it is written to physical tape. As long as a virtual volume remains in the buffer pool, the volume will be recalled from there. The buffer pool size and location is set at installation time, but it can be dynamically extended across any combination of storage devices in the environment. When the disk buffer pool reaches the maximum size, BrightStor CA-Vtape reclaims space by deleting the least recently used virtual volume that has been copied to a physical tape. Large tape data sets are segmented into multiple virtual volumes, allowing those that have completed processing to be de-staged to physical tape, while subsequent volumes for that data set continue processing. Dataspaces z/os and OS/390 dataspaces act as high-speed memory buffers for BrightStor CA- Vtape. When a mount occurs, BrightStor CA-Vtape creates a dedicated dataspace for each virtual device. As applications read or write a virtual volume, data is moved between the dataspace and the disk buffer pool. Datasets These are Virtual Storage Access Method (VSAM) linear data sets (LDS) that contain all the data for BrightStor CA-Vtape virtual volumes, including control and indexing information. These LDSs are preallocated and cataloged in the disk buffer using standard VSAM services. Once the virtual volume is copied to a physical tape, the virtual volume LDS may be reclaimed. Maintenance Maintenance can be dynamically applied and refreshed. Virtual Allocation Management New Allocations Retrieving Established Data Sets Multivolume Output Processing For scratch tape mounts, BrightStor CA-Vtape selects the virtual volume serial number from an internal list of scratch candidates, which are synchronized by the tape management system. To satisfy the virtual volume scratch allocation, BrightStor CA-Vtape selects 10 VSAM LDSs from the available cell list and opens the virtual volume. A BrightStor CA-Vtape display panel shows which virtual volumes are in the buffer pool, their size, data set names, virtual Volume Serial (VOLSER) numbers and status. When an application requests an established data set, the operating system finds it in the Job Control Language (JCL) or Integrated Coupling Facility (ICF) catalog and provides the requested virtual volume to BrightStor CA-Vtape. Once selected, the operating system positions the tape in the correct file sequence, mounts the virtual volume and begins the data transfer. BrightStor CA-Vtape forces an End-of-Volume condition during output processing when the pre-defined maximum file size is met. In small buffer pools, small volume sizes will force multivolume segmentation early so the initial virtual volumes can be moved to physical tape while the job continues on subsequent virtual volumes. BrightStor CA-Vtape supports up to 43 files per virtual volume. 8 October

4 Table 2: Features and Functions: Computer Associates BrightStor CA-Vtape Virtual Tape System Base-System Facilities Close Processing Disk Buffer Pool Status Virtual Volume Stacking Data Protection Duplexing Copies Disaster Recovery Considerations Export Copies Recycle Process All data is synchronized and written to the virtual volume in the disk buffer pool at tape mark processing. As a result, all of the data is on disk before the virtual volume is dismounted. BrightStor CA-Vtape supports up to 43 files per virtual volume. Using a console command or through an ISPF screen, the operator can determine the current buffer pool status, which jobs are using virtual devices, the status of each job, which physical tapes are being used for stacking and the percentage of work completed for those tapes. The BrightStor CA-Vtape stacking format allows access to multiple virtual volumes on a physical tape. During the externalization process, virtual volumes are stacked together based on their stacking group and retention period. Stacking groups allow data sets with similar characteristics and requirements to be stacked together. The management of the stacking process consists of: Expiration dates (short, medium, long) may automatically separate data sets to different physical tapes. Desired Esoteric that is, automatic vs. manual device. Desired Storage Location that is, local vs. disaster vault. User-assigned separator group that is, a user may wish to ensure that the second copy of a database log is on a different physical tape than the primary copy. In the event of a damaged stacked physical volume, BrightStor CA-Vtape has a unique utility that enables the rebuilding of the damaged media either from the duplexed or primary volume, minimizing data loss. Duplexing creates a second, stacked physical tape copy of the data sets in a local or remote site for media or disaster recovery. Duplex copies may be used in any z/os and OS/390 system containing BrightStor CA-Vtape, and these copies can even be on different medium than the primary copy. Because it is a software-based virtual tape system, BrightStor CA Vtape does not require replicated hardware at a disaster recovery/business resumption site. BrightStor CA-Vtape can use any z/os and OS/390 attached hardware for DASD cache and for the backup/restore process. A separate, uncataloged copy of a virtual volume can be copied in native Multiple Virtual Storage (MVS) format. This provides a method for tapes originally placed on a virtual volume to be sent off-site for third-party processing. Recycle consolidates fragmented physical tapes to recover free space. Recycled tapes can be returned to the tape management system s scratch pool and reused. A Recycle Report is generated. A simulation process is also available to determine if running the Recycle Process is needed. Analysis Full-function enterprises are always looking for ways to reduce overhead expenses in their informationprocessing operations. BrightStor CA-Vtape is a perfect fit for this effort. It is a comprehensive, flexible and easy-to-use virtual tape system and, according to CA, the only full-functioned software-based solution 8 October

5 available today. Its capability to use established resources could save users money by not having to purchase that additional unwarranted hardware, resulting in savings of large amounts of operating expense. It is easy to install and is easily expandable when the installation s business grows. The fact that applications do not have to wait for physical tape reads of data from physical tapes, but rather can start operating on data from virtual volumes, is another cost and timesaving feature. There are just two competitors in this market. Both are hardware-based systems StorageTek s VSM and IBM s VTS. Since they are hardware-based, additional hardware is required in the increments that the vendor dictates. When it is time to expand the system, additional proprietary hardware must be acquired. Both are more expensive entries into the virtual tape arena. New hardware means more cost, additional training, installing and configuring. Pricing BrightStor CA-Vtape pricing is based on the amount of Virtual Tape Devices and is $4,300 per device. GSA Pricing Yes. Competitors IBM VTS StorageTek VSM Strengths Ease of installation and use Savings in time and hardware use Expandability A total software implementation Limitations It takes a learning process for those tape-heavy installations to realize that BrightStor CA-Vtape is not a replacement for the established tape management system, but rather a complement to enhance productivity. Insight According to CA, BrightStor CA-Vtape is currently one of its fastest-selling products in the mainframe area because it addresses three critical tape issues plaguing mainframe shops tape access speed, tape bottlenecks and underutilized high-capacity tapes. BrightStor CA-Vtape eliminates waits as well as allowing customers to more fully utilize their expensive high-capacity tapes by stacking many virtual volumes on a single physical volume. BrightStor CA-Vtape allows customers to use whatever z/os attached tape and DASD hardware they currently have installed to implement a virtual solution. It is software-based, not tied to any proprietary hardware and gives customers a variety of choices. 8 October

6 Because of its special position being a software-based virtual solution vs. a hardware-based system and because of all the benefits that go along with that, there should be a bright outlook for the acceptance of BrightStor CA-Vtape. 8 October