IBM System Storage LTO Ultrium 6 Tape Drive Performance White Paper

Transcription

1 IBM System Storage September, 212 IBM System Storage LTO Ultrium 6 Tape Drive Performance White Paper By Rogelio Rivera, Tape Performance Gustavo Vargas, Tape Performance Marco Vázquez, Tape Performance IBM Guadalajara

2 Page 1 Table of Contents Introduction...1 LTO-6 Tape Drive Overview...1 Performance Overview...2 Performance Evaluation...2 FC Data rate Performance...4 SAS Data Rate Performance...9 Tape Capacity...13 Locate and Rewind Performance..14 Load/Unload Performance...15 Speed Matching Performance...16 Conclusions...17 Introduction This white paper describes the performance of the IBM System Storage LTO Ultrium 6 tape drive (LTO-6 tape drive) working on open systems environments. LTO-6 Tape Drive Overview The sixth generation IBM LTO-6 tape drive offers a great storage capacity and an excellent performance using technology designed for the mid range open systems environment that include IBM System p, IBM System i and IBM System x servers; selected Oracle and Hewlett Packard servers and Intel servers running supported versions of Microsoft Windows or Linux. There are 2 interfaces available for the LTO-6 tape drive: 8Gb Fibre Channel (FC-8) 6Gb SAS Both interfaces are available on half and full heights models. The IBM LTO-6 tape drive offers a native data rate of up to 16 MB/s an increase of 14% over the previous IBM LTO-5 tape drive. The LTO-6 tape drive features hardware encryption of data, two interface options, and two form factors. The data rate improvement from the previous generation is 14% and the tape capacity also increases 67% from the previous generation 5. The IBM LTO-6 tape drive offers a new generation of data cartridge (gen6 media) that offers a native capacity of 25GB (625GB with compression) 1.7x the capacity of the previous gen5 tape cartridge generation. This new capacity is achieved in the same tape length (846m) as the gen5 media due to a higher density format (gen6 format). The IBM LTO-6 tape drive will support the Linear Tape File System (LTFS) which presents the tape storage as a file-based storage system. Additionally the IBM LTO-6 tape drive is able to read and write previous generation 5 media and read only generation 4 media to help customers protect their existing tape investments.

3 Page 2 Performance Overview The key features of the IBM LTO-6 tape drive are designed to improve performance and capabilities when compared to the IBM LTO-5, IBM LTO-4 and other vendors tape drives, some of the improvements are: Native data rate of up to 16 MB/s Native data physical capacity of 25GB The data compression engine improvements- data that compresses with LTO-5 drives at should now compress at Faster tape drive mechanism (9 m/s for half height drives) which results in quicker locate and rewind times Support for 8Gb FC and 6Gb SAS connectivity SkipSync Function to provide small file backhitchless flush capability Cache buffer: 124MB (full height models) and 512MB (half height models) This white paper examines the performance benchmarks of the IBM LTO-6 tape drive and associated features. The performance of the different drive host interface types will also be closely examined. Performance Evaluation All the performance benchmarks were run on one or more of the following systems: Server IBM System x385 running Linux RHEL 6.1 with an LSI SAS i4e HBA and a QLogic QLE2562 8Gb FC HBA. Server IBM System x3755 running Linux SUSE 11 SP1 with an LSI SAS 92-8e HBA and a QLogic QLE2562 8Gb FC HBA. Server IBM System x325 running Linux SUSE 11 SP2 with a QLogic QLE2562 8Gb FC HBA.

4 Page 3 The performance benchmarks used for the tests are a toolbox of inhouse C-based performance measurement tools designed to fully exercise the host interface and tape drive with the least amount of overhead. As such, the primary goal of the benchmarks was to provide a picture of the maximum capabilities of the LTO-6 tape drive. All data rates/capacity reflect a decimal basis where MB = 1,, bytes and GB=1, MB. Actual tape drive data rate and cartridge capacity might vary depending on factors such as data compression, server and disk performance variables. There are a number of factors that impact performance, especially data rate at high compression ratios and large block sizes. Server hardware performance, server slot and operating system/device driver performance are important factors. Another source of variability in the data rate performance tests could be due to the firmware used for the Fibre Channel and SAS connections. Since this white paper is primarily concerned with looking at LTO-6 tape drive capabilities, it is beyond the scope of this whitepaper to attempt to present a complete picture of the relative performance characteristics of all possible host server/hba/tape drive combinations. However, when appropriate an attempt will be made to provide some idea of how operating system or HBA selection can affect data rate performance.

5 Page 4 Fibre Channel Data Rate Performance The data rate performance of the IBM LTO-6 Fibre Channel full height tape drive is described by the following set of charts that show how the drive behaves when writing or reading data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes and LTO gen6 media. LTO6 FC FH Write Data Rates Gen6 Media The IBM LTO-6 tape drive achieves a native data rate of 16 MB/s with LTO gen6 media. Higher rates are reached with compressible data and the new compression engine. LTO6 FC FH Read Data Rates Gen6 Media

6 Page 5 The following charts show the IBM LTO-6 Fibre Channel full height tape drive performance when writing or reading LTO gen5 media with data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes. LTO6 FC FH Write Data Rates Gen5 Media The LTO-6 drive can read and write LTO gen5 media at the LTO generation 5 operating point. With no compressible data a data rate of 14 MB/s is achieved. LTO6 FC FH Read Data Rates Gen5 Media

7 Page 6 The following set of charts show streaming data rate performance of the IBM LTO-6 Fiber Channel half height tape drive when writing or reading data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes and LTO gen6 media. LTO6 FC HH Write Data Rates Gen6 Media The half height form factor drive provides similar streaming performance as compared with the full height drive. LTO6 FC HH Read Data Rates Gen6 Media

8 Page 7 The following set of charts describe the IBM LTO-6 Fibre Channel half height tape drive performance when writing or reading LTO gen5 media with data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes. LTO6 FC HH Write Data Rates Gen5 Media The half height form factor drive can read and write LTO Gen5 media with similar rates as compared with the full height drive with LTO Gen5 media. LTO6 FC HH Read Data Rates Gen5 Media

9 Page 8 The above performance benchmarks show IBM LTO-6 Fibre Channel tape drive performance (full height and half height models) from one or more of the systems: IBM system x385 running RHEL 6.1 with a QLogic QLE2562 HBA, IBM system x3755 running SUSE 11 SP1 with a QLogic QLE2562 HBA and IBM system x325 running SUSE 11 SP2 with a QLogic QLE2562 HBA. It must be noted that results from the IBM system x385 for compression ratio at 512KB block size dropped about 9% from those shown, however, the rest of the data rates for all the compression ratios and block sizes were consistent on all systems. In this case, some aspect of the host-side configuration decreased the system data rate performance for the specific case mentioned.

10 Page 9 SAS Data Rate Performance The data rate performance of the IBM LTO-6 SAS full height tape drive is described by the following set of charts that show how the drive behaves when writing or reading data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes and LTO gen6 media. LTO6 SAS FH Write Data Rate Gen6 Media The SAS data rate performance capability of the IBM LTO-6 full height drive meets expectations at all compression ratios. LTO6 SAS FH Read Data Rate Gen6 Media

11 Page 1 The following charts show the IBM LTO-6 SAS full height tape drive performance when writing or reading LTO gen5 media with data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes. LTO6 SAS FH Write Data Rates Gen5 Media The LTO-6 SAS full height drive meets the LTO gen5 data rates expectations when using LTO gen5 media. LTO6 SAS FH Read Data Rates Gen5 Media

12 Page 11 The following set of charts show streaming data rate performance of the IBM LTO-6 SAS half height tape drive when writing or reading data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes and LTO gen6 media. LTO6 SAS HH Write Data Rates Gen6 Media The LTO-6 SAS half height form factor drive provides similar streaming performance as compared with the SAS full height drive. LTO6 SAS HH Read Data Rates Gen6 Media

13 Page 12 The following charts show the LTO-6 SAS half height tape drive performance when writing or reading LTO gen5 media with data that compresses uniformly at ratios,,, and maximum (8:1) using differing block sizes. LTO6 SAS HH Write Data Rates Gen5 Media LTO6 SAS HH Read Data Rates Gen5 Media

14 Page 13 Tape Capacity The following chart shows the capacity for LTO gen6 and LTO gen5 media measured with the LTO-6 tape drive. Tape capacity is obtained by writing 256KB blocks of uncompressible data until an error code is returned when EOT (End Of Tape) is reached. The LTO-6 tape drive with gen6 media increases about 67% over gen5 tape cartridge capacity offering a native physical capacity of 25GB while maintaining the 15 GB expectation with gen5 media. Tape Capacity 25 2 The LTO-6 tape drive with gen6 media offers a significant capacity increase over gen5 media. Capacity (GB) 15 1 Gen6 Media Gen5 Media 5 FC FH FC HH SAS FH SAS HH

15 Page 14 Locate and Rewind Performance The following charts show the average time for the LTO-6 drive to locate a random block id on the tape starting at BOT (Beginning Of Tape), the average time to locate a random block id starting at some random location on the tape, the average rewind time as well as maximum times measured for the three operations. To determine average and maximum times, plenty locate and rewind operations were made on a completely filled tape. The full height form factor drives offer faster locate and rewind performance than the half height form factor drives when using LTO gen6 media. With LTO gen5 media, a similar difference is observed. LTO6 SAS and FC Locate and Rewind Times Gen6 Media Seconds FH FC HH FC FH SAS HH SAS The full height form factor drives offer faster locate and rewind performance than the half height form factor drives when using LTO gen6 media. Avg BOT Locate Avg RND Locate Avg Rewind BOT Locate RND Locate Rewind LTO6 SAS and FC Locate and Rewind Times Gen5 Media 12 1 Seconds FH FC HH FC FH SAS HH SAS Avg BOT Locate Avg RND Locate Avg Rewind BOT Locate RND Locate Rewind

16 Page 15 Load and Unload Performance The following charts show the tape cartridge load and unload times for the LTO-6 tape drive with LTO gen6 and LTO gen5 media. The performance when loading a cartridge is slightly better for the full height drives. The time to unload a cartridge is faster for the full height drives and there is no significant difference regarding the interface type used. LTO6 SAS and FC Load and Unload Times Gen6 Media Seconds LTO6 HH FC LTO6 FH FC LTO6 HH SAS LTO6 FH SAS 5 The IBM LTO-6 tape drive has good load performance for all form factors, generation media and interface types. The time to unload a cartridge is faster for the full height form factor drives for both gen6 and gen5 media. Load Time Unload Time LTO6 SAS and FC Load and Unload Times Gen5 Media Seconds LTO6 HH FC LTO6 FH FC LTO6 HH SAS LTO6 FH SAS 5 Load Time Unload Time

17 Page 16 Speed Matching Performance The IBM LTO-6 tape drive disposes of 14 defined speeds to match the host data rate. The implementation of this feature allows to reduce the number of backhitches when the net host data rate is less than the maximum drive native data rate, reducing unnecessary tape motion, and may increase overall performance in certain environments. To perform this test, host delays are used to vary the speed of the data from the host to the LTO-6 tape drive. At each host data rate the number of datasets handled by each speed is recorded (A dataset is the unit of writing for the drive on the physical tape side and consists of collection of logical blocks, file marks, ECC, and other format attributes). The Y-axis shows both the effective data rate and the number of datasets handled by each speed for the host data rate (X-axis). The chart shows how the drive selects the appropriate speed from the available 14 speeds to match the host data rate and most of the datasets written are handled by the suitable speed. Speed matching helps to improve the overall tape drive data rate at lower host data rates. Dataset Count LTO6 FC FH Write Speed Matching Host s1 s2 s3 s4 s5 s6 s7 s8 s9 s1 s11 s12 s13 s14 DR

18 Page 17 Conclusions Since the introduction of the first IBM LTO tape drive, every following generation has incorporated new features and performance improvements to respond storage needs, now the IBM LTO-6 tape drive in conjunction with the new LTO gen6 media represents an efficient solution for todays growing storage demands. Native capacity increase from 15GB (gen5 media) to 25GB (gen6 media) and even more with data that is compressible (625GB with compression) while maintaining the same tape length (846m). This capacity increase does not impact locate/rewind performance and the faster mechanism for the half height form factors improves performance for tape motion operations (locate/rewind times) from previous half height drive generations. In addition, the IBM LTO-6 tape drive continuous to support media partitioning, encryption of data and WORM media. All the improvements make the IBM LTO-6 tape drive suited for handling backup, restore, and archive of higher data capacities at higher data transfer rates as compared with the previous LTO-5 tape drive.

19 Page 18 International Business Machines Corporation 212 IBM Systems Group 56 Cottle Road, San Jose, CA Printed in the United States of America 5-7 All Rights Reserved IBM, the IBM logo, IBM System i, IBM System p, IBM System x, System Storage are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both. Linear Tape-Open, LTO, the LTO Logo, Ultrium and the Ultrium logo are trademarks of HP, IBM Corp. and Quantum in the U.S. and other countries. Microsoft, Windows, Windows NT, and the Windows logo are trademarks of Microsoft Corporation in the United States, other countries, or both. Other company, product and service names may be trademarks or service marks of others. Product data has been reviewed for accuracy as of the date of initial publication. Product data is subject to change without notice. This information could include technical inaccuracies and/or typographical errors. IBM may make improvements and/or changes in the product(s) and/or programs(s) at any time without notice. References in this document to IBM products, programs, or services does not imply that IBM intends to make such products, programs or services available in all countries in which IBM operates or does business. Any reference to an IBM Program Product in this document is not intended to state or imply that only that program product may be used. Any functionally equivalent program, that does not infringe IBM s intellectually property rights, may be used instead. It is the user s responsibility to evaluate and verify the operation of any non-ibm product, program or service. The performance data contained herein was obtained in a controlled, isolated environment. Actual results that may be obtained in other operating environments may vary significantly. While IBM has reviewed each item for accuracy in a specific situation, there is no guarantee that the same or similar results will be obtained elsewhere.

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