Enterprise Class SSD, the Key Solution for Cloud Computing Storage Systems

Transcription

1 212.8 Enterprise Class SSD, the Key Solution for Cloud Computing Storage Systems Page 1

2 Introduction In enterprise-operated data centers and cloud computing systems, demand for high capacity/high performance storage is on the rise due to the information explosion. At the same time, low power consumption and small footprints are in high demand to reduce the total cost of ownership (TCO). However, high capacity/high performance and low power consumption/small footprints are conflicting requirements. By increasing the number of. storage devices, high capacity can be achieved, but doing this will never achieve low power consumption and small footprints. Thus, realizing a storage solution that can balance high capacity/high performance and low power consumption/small footprints is now recognized as a challenge. Market requirements Requirements for storage devices - Ability to handle expanding data High capacity storage - Enhanced cloud access performance High performance storage - Reduced TCO Low power consumption/small footprints Figure 1 The Information Explosion and Requirements for Storage Devices Introducing Enterprise Class Solid State Drives (s) computer systems consist primarily of main memory (DRAM) and enterprise hard disk drives (s). In such systems, as the difference between data access speeds between DRAM and s is five orders of magnitude, the following problems are caused when storing medium-speed data. Storing medium-speed data in expensive DRAM increases data costs, while storing data on s degrades performance. Thus, the differences in speed among storage media become a bottleneck in system optimization. To resolve this problem, the leverage of solid state drives (s) for enterprise use has Page 2

3 begun in earnest. s employ NAND flash memories as storage media. For example, Figure 2 shows a comparison of data access performance (data read time). As shown in the figure, s have a performance level between that of DRAM and s. By introducing s, the bottlenecks between DRAM and s are eliminated, allowing system optimization. DRAM s 高速回転 s High-capacity 大容量 HDDs HDD ( *1 ) nsec 5 order-of-magnitude difference 3 order-of-magnitude difference μsec msec 1E-9 1E-8 nsec 1E-7 1E-6 1E-5 μsec 1E msec.1 Use of s eliminates a performance difference of 5 orders of magnitude *1 :Near Line HDD Figure 2 Data Access Performance While s have advantages when used as bulk storage, s exhibit both excellent access performance and power consumption efficiency (random read speed/power consumption). Combining s and s such that their advantages complement one another can enhance system performance. : Excellent : Good : Mildly unsatisfactory : Poor The following grades are in comparison to s. s are given a grade of /Good. (Research by Toshiba) Feature Comparison Random Access Performance Power Consumption Device Costs TCO Reduction Effects Sequential Access Per Access Performance Per Storage Capacity Per Access Performance Per Storage Capacity High-speed Processing High-capacity Storage High-capacity HDD() Figure 3 Comparison of Characteristics Page 3

4 System Configurations Leveraging s In server applications, s can be replaced with s. In storage systems, s can be used in combination with s. In either case, s offer an effective solution for eliminating the access performance bottlenecks of s. Therefore, s have high market potential. Servers: Data processing Application processing CPU Memory cache CPU ICH (I/O Controller Hub) High-speed application loading High processing performance for many clients Storage I/F OR SAN *2 (FC/iSCSI) Storages: Read/write of data to/from servers Mass storage Memory cache ICH I/O Controller Hub) Storage I/F High-speed data read/write and fast responses High access frequency data Low access frequency data Tiered Storage System Tiered Storage Systems *1) SAN: Storage Area Network Figure 4 Configurations of s in Enterprise Systems (image) The system s access performance will be dramatically improved if all s are replaced with s. However, the total cost of such a system will be very expensive, because less-frequently accessed data, which does not require high-speed performance, will be stored on expensive s. In a storage system, not all data is accessed with the same level of frequency. Generally, data can be classified into the following three classes: high, medium, and low access frequency data. By making use of this characteristic of data, it is possible to build an effective high-performance, cost-effective system by storing high access frequency data on s, medium access frequency data on s, and low access frequency data on high-capacity HDDs (s). Figure 5 shows an example of a tiered storage system that consists of s, high-speed HDDs, and high-capacity HDDs. These are tiered to respectively constitute 5%, 15%, and 8% of the total system capacity. Although capacity accounts for only 5% of the total, accesses to the s account for 5% of all accesses to the system. Still, 8% of the total system capacity is realized with inexpensive, high-capacity HDDs. Page 4

5 Data access locality Capacity 容量 Accessアクセス頻度 Frequency 5% 15% 5% 8% 3% 2% Tiered 階層システム Storage System % 2% 4% 6% 8% 1% IOPS Mix. operation 7% Read, 3% Write 68k IOPS/units Figure 5 Data Access Frequency and Example of a Tiered Storage System Effects of Tiered Storage Systems and Reduced Power Consumption Figure 6 shows how much the performance of a tiered storage system can be improved by combining s and HDDs rather than maintaining a conventional 1% storage system. The following calculations assume a 2 TB tiered storage system configured in the above-mentioned proportions. The improvements in (1) power consumption, (2) footprint size, (3) access performance, and (4) power consumption efficiency (access performance/power consumption) are as follows. Although s account for only 5% of the system s total capacity, they dramatically improve system performance and power consumption. (1) Electricity use Reduced 4% Low power consumption (2) No. of drives Reduced by half Small footprints (3) Access performance Increased 17 High performance (4) Power consumption efficiency (Random read speed/power consumption) Increased 26 Page 5

6 - Tiered Storage System with s - Enterprise HDD Storage System Tiered System System Storage configuation Drive Capacity QTY Ratio 1k RPM HDD 6GB 334 1% Power consumption [ W ] ,5W Tiered 階層 Power saving Reduced 4% 2,34W Number of Slot (drives) [ units ] (QT Y) Tiered 階層 334(QT Y) Small footprint, fewer slots No. of drives reduced 5% System total IOPS [ k IOPS ] ,73k Tiered 階層 1k High performance, access speed Increased 17 Power efficiency [ IOPS/W ] 1,4 1,2 1, ,156 階層 Tiered 43 Power consumption efficiency Increased 26 Figure 6 Effects of Tiered Storage Systems (assumes 2 TB storage systems) Key Features of Toshiba s Toshiba s provide best-in-class reliability and performance via the following technologies. (1) High capacity/high performance: Toshiba has applied 32-nm NAND flash memory technologies to s ahead of its competitors, achieving capacities as high as 4 GB. To realize both low power consumption and high performance for each drive, Toshiba has applied 16-parallel read/write processing technologies to NAND flash memory. Among its achievements, an average power consumption of 6.5 W, I/Os per second (IOPS) as high as 9,, and a sequential read transfer rate of 51 MB/s are the best *3 in the industry. (2) Longer product lifetimes: In addition to single level cell (SLC) NAND flash memory technology, which exhibits an excellent write operation property lifetime, sophisticated firmware-driven write wear-leveling (WL) technologies allow the drive to continuously operate 24 hours a day for as many as 5 years. (3) Excellent reliability: An error detection/correction function is enabled on all data transfer paths in both NAND flash memories and devices. On top of that, a Toshiba-specific data protection function allows data to be recovered if a NAND flash memory should accidentally fail. As the above suggests, Toshiba has achieved high reliability exceeding that of HDDs, the conventional storage product. *3: December 21 research by Toshiba Page 6

7 Connector Uses Serial Attached SCSI (SAS) connectors High-speed communication via 6 Gbps Dual Ports Controller NAND controller High-reliability SSD with a 16-parallel processing architecture and NAND lifetime control/error correction technologies NAND Flash Memory NAND flash memory for storing data Low power consumption thanks to the NAND 32-nm process High reliability realized by Single Level Cell (SLC) technology Exterior 2.5 Small Form Factor (SFF) Easy system replacement can be performed thanks to compatible shapes Figure 7 Overview of Toshiba Enterprise SSDs (s) Conclusion Introducing s allows one to eliminate the bottlenecks of conventional storage systems. Deploying s, which have a performance level between that of DRAM and s, can enhance system performance. As this article explains, tiered storage systems, which combine high-speed s with high-capacity HDDs, allow low power consumption/small footprints and high performance to be achieved more efficiently than conventional storage systems of the same capacity. In addition, Toshiba offers a complete line-up of enterprise-oriented storage products to allow tiered storage systems to be configured. Clients may also select high-capacity storage devices according to their applications and the scale of their systems. Going forward, Toshiba will continue to develop a series of storage products featuring both high performance and high reliability for enterprise use. Market requirements Requirements for storage devices - Ability to handle expanding data High capacity storage - Enhanced cloud access performance High performance storage - Reduced TCO Low power consumption/small footprints These requirements can be realized using tiered storage Page 7