| In an article titled "No Waiting: | | | | modules used in our comparative |
| Considering the Benefits of Solid State | | | | analysis. |
| Disks,"1 authors Ramon Sandoval and | | | | |
| Maneesha Lee highlighted the growing | | | | In this study we have selected 15,000rpm |
| popularity of solid state disks (SSDs) | | | | drives, the fastest available rotational |
| as accelerators for enterprise | | | | hard drives in the market today. Both |
| databases. The authors cited the rapid | | | | drives feature Fibre Channel interfaces |
| expansion of the SSD industry as a | | | | and are enclosed in the same 3.5-inch |
| result of relational database | | | | form factor. Since this analysis will |
| applications, with SSDs being deployed | | | | focus more on cost versus IOPS |
| as storage devices for hot files2. In | | | | performance alone, disk capacity is |
| particular, Sandoval and Lee revealed | | | | totally irrelevant in this analysis. |
| that a major portion of enterprise SSDs | | | | To cancel out the advantages (and |
| are installed in high-end database | | | | disadvantages) brought by JBOD modules |
| applications running Sybase, Oracle and | | | | from different manufacturers, this |
| Informix, along with SAP running on top | | | | analysis will utilize a generic JBOD |
| of these databases. | | | | module that has the same form factor |
| Aside from this write-up, several | | | | (2U) and disk capacity (12 3.5" disks) |
| reports and white papers emphasizing the | | | | as the E-Disk(R)SAN S2F-J from BiTMICRO. |
| performance benefits of SSDs have | | | | |
| already been published, and hard disk | | | | Disk/Module Performance |
| drive makers such as Samsung have | | | | There has been a dearth of storage |
| expressed interest in this storage line. | | | | hardware literature that tackles HDD |
| The only remaining question is, are SSDs | | | | performance as measured in I/Os per |
| a viable alternative for price-conscious | | | | second, as most drive manufacturers |
| buyers who are running | | | | publicize disk performance in terms of |
| performance-hungry OLTP apps? | | | | MB per second (MBps). However, IOPS |
| The objective of this article is to | | | | statistics are critical in random access |
| examine the benefits of utilizing flash | | | | applications such as OLTP and data |
| SSD-enabled storage system as cache | | | | warehousing, and storage subsystem |
| storage in an enterprise environment. A | | | | suppliers post mission-critical IOPS |
| comparison will be made between | | | | data in their website. Similarly, |
| conventional storage systems (featuring | | | | BiTMICRO Networks conducted benchmark |
| HDDs) and solid-state disk-based network | | | | tests in November 2003 for its |
| storage in terms of performance and | | | | E-Disk(R)SAN featuring twelve E-Disk |
| overallcost per IOPS. | | | | Fibre Channel channels. IOPS results for |
| Market Trends | | | | a small-block (4KB), sustained random |
| Storage users are buying more midrange | | | | read workloads are posted in the |
| and lower cost systems, according to | | | | succeeding table. |
| International Data Corp.'s (IDC) | | | | |
| quarterly worldwide disk storage systems | | | | To compute for the generic JBOD's |
| report released December 2004. Revenues | | | | performance rating, we multiplied the |
| grew 3.5 percent year-over-year to $3.4 | | | | 15,000RPM HDD's maximum IOPS rating of |
| billion in the third quarter of 2004. | | | | 435 with the maximum number of disks in |
| Although revenue growth was smaller | | | | the enclosure (12). The result, 5,220, |
| compared to previous quarters, IDC noted | | | | is the theoretical maximum IOPS for |
| rapid growth in storage capacity, rising | | | | small block (4KB) random reads. |
| 50.5 percent year over year to 310 | | | | Table 3 figures already show a wide |
| petabytes. It is the largest growth rate | | | | disparity in I/O ratings (more than |
| posted over the last seven quarters, the | | | | 1100%) both at the drive and at the |
| report said. | | | | enclosure levels. To achieve the desired |
| IDC analyst Brad Nisbet says the results | | | | performance of 100,000 IOPS, we simply |
| confirm the slow but steady growth of | | | | add more enclosures and drives in the |
| midrange and lower segments, like | | | | JBOD setup accordingly (Table 4). |
| ATA-based storage. "We saw an increase | | | | |
| in the growth of petabytes shipped, | | | | To compute for the dollar cost per IOPS, |
| which is yielding the largest dollar per | | | | we add up the equipment cost and divide |
| gigabyte pricing decline in seven | | | | the amount by the total IOPS generated. |
| quarters and points to a growing share | | | | Equipment includes the drives, |
| of higher-capacity, lower-cost disk | | | | enclosures, switches and cabinet. |
| drive deployments and a broader variety | | | | However, for the purpose of this |
| of products offered by the major | | | | analysis, it is assumed that each setup |
| vendors," he explains. | | | | will utilize one switch. Therefore the |
| Another contributing factor to the | | | | cost of switches may not be included in |
| growth of networked storage, in | | | | the computation since they would just |
| particular midrange systems, is the | | | | cancel each other out. List prices for |
| stiff price competition among sellers in | | | | the generic JBOD setup are based on web |
| their bid to corner a slice of shrinking | | | | prices as of June 29, 2005. |
| IT budgets. Price consciousness is also | | | | |
| echoed in the way enterprises handle | | | | Analysis of Results |
| their storage requirements. | | | | To compute for the $ cost per IOPS, the |
| Consolidation is now a must as it | | | | following formula will be used using |
| increases storage manageability, | | | | figures from Tables 4 and 5. |
| maximizes capacity utilization, and | | | | Total IOPS / Total Cost = $ per IOPS |
| lowers overall TCO. | | | | Table 6 figures reveal a significant |
| However, this strategy puts a strain on | | | | difference in investment costs when |
| server performance, especially for I/O | | | | building a storage system for database |
| intensive applications such as: | | | | OLTP applications using a generic JBOD |
| - Aerospace, telemetry and data | | | | versus an E-Disk(R)SAN. On a $/IOPS |
| acquisition | | | | level, the rotational HDD-based JBOD |
| - Data backup and recovery as well as | | | | array costs 303.8 percent higher than |
| migration | | | | the E-Disk(R)SAN, thanks to the |
| - Energy exploration and geosciences | | | | significantly higher I/O rating of the |
| - Medical sciences, including healthcare | | | | S2F-J solid state disk subsystem which |
| and imaging | | | | resulted in a lower number of drives |
| - Online transaction processing (OLTP) | | | | required. Another factor that drove down |
| - Paging, log, journal and index files | | | | equipment cost is the smaller cabinet |
| - Still and moving video surveillance | | | | space requirement of the S2F-J (24U) as |
| - Video editing and processing, | | | | opposed to the generic JBOD (48U). In |
| including post-production | | | | fact, the SSD-based subsystem can be |
| - Video on demand and video services | | | | easily integrated into existing data |
| - Weather forecasting and simulation | | | | centers since it is composed of only two |
| OLTP is a critical segment in enterprise | | | | 2U modules as compared to the 20 modules |
| storage as most banking, trading and | | | | required for the HDD-JBOD setup. |
| supply chain transactions are now | | | | Removing the 24U cabinet (costing |
| transferred online, with users demanding | | | | $4,298) in the S2F-J setup would drive |
| faster and more responsive systems. In | | | | down $/IOPS even further. |
| selecting the most cost-effective, | | | | Conclusion |
| high-performance storage device for this | | | | Enterprises are looking for ways to |
| application, IT and data center | | | | generate more IOPS in the same data |
| administrators have HDDs and SSDs as | | | | center space, as well as cost-effective |
| options. The wide variety of available | | | | means of scaling their storage |
| models in the market and lower price per | | | | performance requirements. The examples |
| unit makes the HDD as the most logical | | | | in the preceding section prove that |
| solution for enterprises, providing the | | | | solid state flash disks are cost |
| best return on investment. Or does it? | | | | effective solutions for performance |
| Cost Analysis | | | | hungry applications, not only in terms |
| Let us examine a setup involving a | | | | of $/IOPS in general, but also for |
| generic SAN attached JBOD setup | | | | deferring costly server upgrades in I/O |
| comprised entirely of 15,000RPM | | | | bound applications. This article focuses |
| rotational HDDs as opposed to a BiTMICRO | | | | mainly on the cost advantages of the SSD |
| E-Disk(R)SAN S2F-J featuring flash-based | | | | subsystem in an equipment level. The gap |
| E-Disk SSDs. The objective of this | | | | between SSDs and HDDs widens further |
| analysis is to compare the capital | | | | when other factors such as power |
| investment needed to acquire a networked | | | | consumption of 220 rotational hard |
| storage solution that can offer peak | | | | drives versus 21 solid-state flash |
| performance of 100,000 IOPS in a typical | | | | disks, storage space (and the burden |
| OLTP/database I/O application. | | | | that these subsystems will impose on the |
| Hardware Specifications | | | | data center's cooling system), and |
| The tables below detail the technical | | | | better reliability (MTBF) are taken into |
| specifications of the drives and JBOD | | | | consideration. |