Tape Drive Selection — a How-To Guide
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Tape Drive Selection — A How-To Guide THE CLIPPER GROUP TM SMSM Explorer SM Navigating Information Technology Horizons Published Since 1996 Report #TCG2004040 May 7, 2004 Tape Drive Selection — A How-To Guide Analyst: David Reine Management Summary Tape is an essential medium for the data center. It is as important to the secure operation of the computer room as tires are to the safe operation of an automobile, with as many or more choices. Both are commodity products. Goodyear sells tires that will fit on everything from a Chevrolet to a Lexus. Bridgestone sells tires that fit a Toyota or a Mercedes. Likewise, Quantum sells tape drives that will operate with anything from a Dell PC to an IBM eServer. Exabyte sells tape products that will work with any UNIX box. You can even buy an IBM 3592 drive in an IBM frame to work with a StorageTek library!1 There are a significant number of variables associated with the selection of either. Furthermore, it is not always obvious which variable is the most significant. The first option that the tire shopper faces is the warranty mileage. Does he want a tire that has a 20,000, 40,000, or 50,000-mile warranty? The first reaction might be to select the tires that will last the longest. However, they will probably cost the most! It is important to understand how many miles the car will drive over the next year. It is important to calculate how many more years that the driver will continue to own this car. If you drive 15,000 miles a year and want to keep the car for two more years, then a tire rated at 40,000 miles could be perfect. Moreover, the shopper also needs to evaluate how the tires will perform, given the specific expected driving conditions. Do you need high-performance tires or standard highway tires? Do you drive in snow? Will the tires hold the road well in slippery conditions? There are many variables in the tire selection process. The same is true for tape. It is safe to assume that every data center today uses tape. However, for what purpose does the data center use tape? Is it a backup drive? Is it a data processing device? How much data needs to be stored? How long is the backup window? Is the tape drive used in a pure open systems environment or is there a mainframe lurking in the shadows with connection requirements? Moreover, the question that every CIO is asking is, “How much more will my data expand over the coming years”? The requirements placed upon every enterprise by laws such as Sarbanes-Oxley and the Patriot Act have forced these enterprises to double and triple, if not more, their backup and data protection projection. IN THIS ISSUE There are many formats for tape: SDLT, LTO, SAIT, as well as 3592 and T9940B. This ¾ Today’s Data Center Environment ........2 issue of The Clipper Group Explorer will ¾ New Tape Architectures .........................2 take an in-depth look at the various options that • SDLT...................................................2 the different formats present to the data center • LTO.....................................................3 and try to help you in your selection process. If • SAIT....................................................4 you are looking to review or upgrade your tape • 3592 ....................................................5 environment, please read on. • T9940B ...............................................5 ¾ Conclusion ..............................................6 1 But see box on page 5. The Clipper Group, Inc. - Technology Acquisition Consultants Strategic Advisors 888 Worcester Street Suite 140 Wellesley, Massachusetts 02482 U.S.A. 781-235-0085 781-235-5454 FAX Visit Clipper at www.clipper.com Send comments to [email protected] May 7, 2004 The Clipper Group ExplorerTM Page 2 Today’s Data Center Environment the cost of tape on a $/GB basis has been driven Enterprises today are gathering an ever-in- well below the $1.00/GB level. In fact, a Super creasing store of information in order to gain a DLTtape cartridge is available for about competitive advantage in their industry and to $.35/GB, while LTO-2 and SAIT cartridges cost increase profitability. Some of this information is even less. associated to mission-critical applications run- How does this compare to disk, for those ning the core of enterprise business. Other data who are looking at local/remote disk options as a relates to improving customer and vendor permanent back-up/recovery option? Open relationships. Enterprises retain even more data systems disk prices have come down signif- in order to protect themselves from potential icantly, but not as far as tape! A typical Fibre government action. The data center staff must Channel (FC) disk device, in an array, will cost protect all of it in order to assure the financial between $20-$30/GB, depending on whether you health of the enterprise. select 10K or 15K RPM drives. In a multi-tier Legislation, such as Sarbanes-Oxley and the ILM environment, you can also select an ATA Patriot Act, require enterprises to preserve their solution that could reduce that cost to about financial data for long periods. Health protection $6.00/GB, with significantly less functionality. acts such as HIPPA place special import not only This media cost is still about 5 times that of tape. on the retention of health records, but also on the Furthermore, once your data center has made the privacy of such information. In January, we initial investment in a tape library, the cost of looked at the role that Information Lifecycle adding incremental tape storage is so low that it Management (ILM) plays in keeping tape alive increases the difference between tape and disk. as a medium in the data center2. At that time, we The decision on which tape format to use examined the generic use of tape as a backup and is primarily made based on the requirement recovery medium as well as a data processing for capacity and performance, although issues medium. We identified some of the reasons for such as reliability and data protection have this rise, such as a renewed importance on developed an increasing importance. There are standard backup-recovery processes, and prot- also some instances when compatibility with the ection from disasters such as 9/11. We also past plays a factor in that decision. A large identified additional topics that we hoped to legacy library of DLT cartridges, for example, cover in later bulletins. In this second issue in a may be a contributing factor to pursue SDLT in series on tape, we examine the different formats the future. Let’s look at some of the new open and architectures that are available to the tape formats that have been introduced since Information Technology (IT) community and try 2000 and how they might fit into your operations. to identify which formats may provide superior SDLT performance in your specific environment. Before 2000, the DLT8000, with a capacity New Tape Architectures of 40GB and a throughput of 6MB/s, was the The turn into the 21st Century has brought with it market leader for backup and recovery, a renewed interest in the development of new, archiving, disaster recovery, and network storage improved tape formats to archive data and to in the mid-range systems marketplace. This insure business continuity. These new formats covered UNIX, Linux, and Windows, among bring to the market a variety of capacity and other open systems. Quantum took that archi- throughput characteristics, with SDLT, LTO, and tecture and enhanced it for better performance SAIT leading the open format charge toward and higher capacity to address growing ILM 1TB cartridges. IBM and STK, meanwhile, requirements in both the enterprise and continue to champion the performance of their departmental/workstation environments. These mainframe and open tape offerings, while at the enhancements took two parallel paths, depending same time, extending them into the open systems upon system needs and budget. The first path, fray. Because of this renewed competition for Super DLT (SDLT), is aimed at enterprise the long-term storage portion of the ILM market, requirements of high performance and high capacity, and has a product roadmap spanning four generations. (See Exhibit 1.) The 2 See The Clipper Group Explorer dated January 29, 2004, entitled The Role of Tape in Multi-Tiered alternative, called DLT VS, aims at entry to mid- Storage – Alive, Kicking, and Rolling Along at range server environments, also delivering http://www.clipper.com/research/TCG2004008. Copyright © 2004 by The Clipper Group, Inc. Reproduction prohibited without advance written permission. All rights reserved. May 7, 2004 The Clipper Group ExplorerTM Page 3 Exhibit 1 – Super DLT Roadmap SDLT320 SDLT600 SDLT1200 SDLT2400 Capacity (GB) 160 300 600 1200 Throughput (MB/s) 16 36 >50 >100 Availability 2002 2004 2005 2007 increased performance and capacity, however, LTO with a reduced cost and better value. With a In 1998, HP, IBM, and Certance (formerly growth path designed to double capacity every known as Seagate RSS) joined forces to create a 18-24 months, SDLT appears to be ideally suited pair of open-format tape specifications. This was to keep pace with expanding enterprise storage driven by the confusing number of formats and requirements, while at the same time protecting technologies that existed in the tape storage investments made by the enterprise in new marketplace. Based on the partnership’s Linear technology. Tape-Open (LTO) technology, and named With an installed base of two million Ultrium and Accelis3, they were designed to legacy tape drives, Quantum designed the bring open standards and new levels of SDLT320 to be backward-read compatible scalability, reliability, and automation to the open with DLT x000, DLT1, and DLT VS80, using systems tape backup market.