Wikibon recently published a report on the Oracle ZFS storage appliance, ultimately giving it a rather positive review. The IT market research firm has been very critical of Oracle products and policies in the past, which makes this recommendation all the more noteworthy. The ZFS’s design is a true “flash-first” hybrid storage architecture. That is an interesting highlight, because Wikibon founder and CTO David Floyer has been extremely bullish on flash-only storage arrays. It clearly shows the importance of flash-first arrays, while also focusing on the flexibility of hybrid storage.

Cost considerations for Oracle ZFS

Because of the true hybrid design of he ZFS Appliance, CIOs will find significant savings relative to traditional disk arrays that don’t scale as well. That’s savings you’ll reap in time and money. It is indeed a true hybrid, allowing high continuous read and write rates with sustained low latency. The Wikibon research concludes with the recommendation that CIOs use the ZFS Appliance in more demanding workloads, where sustained write performance and IO requirements are higher.

Usage examples include high performance environments such as specific backup applications and core transaction-intensive database workloads. The high-end ZFS storage array is the highest-performing hybrid storage device that has been analyzed by Wikibon, and in a class of its own when it come to high write-IO environments.

Introduction To ZFS Storage Appliance

The ZFS Appliance is fundamentally designed with a flash-first hybrid architecture. The read IO cache utilizes MLC SSDs, and the write cache utilizes the higher performing but higher costs SLC SSDs. The ZFS Appliance consists of five components:

• The Oracle ZFS File System and Solaris Operating System
• The Oracle ZFS Appliance management software, including DTrace
• The Oracle 2.5” storage modules for hard disk drives (HDD) and flash read and write storage (SSD)
• Write Optimized Cache consisting of sets of 4 SSDs with 288GB of SLC flash storage, with a maximum write rate of about 1.3 GBytes/second, and a sustained write rate at 70% loading of 1.3 x 0.7 = 0.91 gigabytes/second
• One or more Storage Appliance Controllers, holding up to 1 TB of DRAM each

Worth noting is that of the hybrid and traditional arrays reviewed by Wikibon, only Tintrí has the equivalent quality of data (at a lower configuration level, and for VMware environments only) as Oracle ZFS Hybrid Storage’s DTrace. Wikibon believes that as much as 30 percent of ZFS appliances go into VMware environments; further more, that Oracle has provided quality support in those environments too.

The Oracle ZFS Appliance was tested against the traditional storage arrays/filers that were modeled were modular 2-controller storage systems, based on systems such as the EMC VNX, NetApp FAS 6000 series, etc. Particular attention was paid to ensure the write rate was sustainable, and not just for short bursts. The cost savings are significant.

Total Cost of hybrid vs. traditional storage for…

• 100 TB

Figure 3 shows a comparison between the 4-year total cost of ownership between the hybrid solution and the traditional array/filer solution for an environment with 100 terabytes, 1,000,000 IOPS and 20 percent writes. This is equivalent to 10,000 IOPS/TB, in the middle of the x-axis in Figure 2. Included in the analysis are the cost of maintenance (18 percent/year of capital costs), the implementation cost, the operational costs and the power, space, and cooling costs ($150/sq. ft. per year and 10c/kWh for power, with a PUE of 2.5). The additional cost of the traditional system is 194 percent higher than the hybrid system.

• 200 TB

Figure 4 shows a comparison between the 4-year total cost of ownership between the hybrid solution and the traditional array/filer solution for an environment with 200 terabytes, 2,000,000 IOPS and 35 percent writes. This again is equivalent to 10,000 IOPS/TB, in the middle of the x-axis in Figure 2. Included in the analysis are the cost of maintenance (18 percent/year of capital costs), the implementation cost, the operational costs and the power, space and cooling costs ($150/sq. ft. per year and 10c/kWh for power, with a PUE of 2.5). The additional cost of the traditional system is 241 percent higher than the hybrid system.

• 400 TB

Figure 5 shows a comparison between the 4-year total cost of ownership between the hybrid solution and the traditional array/filer solution for an environment with 400 terabytes, 4,000,000 IOPS and an aggressive 50 percent writes. This again is equivalent to 10,000 IOPS/TB, in the middle of the x-axis in Figure 2. Included in the analysis are the cost of maintenance (18 percent/year of capital costs), the implementation cost, the operational costs and the power, space and cooling costs ($150/sq. ft. per year and 10c/kWh for power, with a PUE of 2.5). The additional cost of the traditional system is 307 percent higher than the hybrid system.

Analyst’s takeaway assessment for CIOs is of high marks:

“CIOs, CTOs and senior storage executives should position the Oracle ZFS appliance as an ideal strategic fit for high streaming environments such as database backups,” Floyer says. “As well, the product can be successfully integrated into high-performance Oracle database workloads. In write-intensive and heavy IO workloads, the ZFS appliance will likely prove the best-of-breed, lowest cost solution. Outside of that sweet spot, traditional midrange arrays and filers will often be a better economic fit.”