By Dave Simpson
—After nearly four years in stealth mode, Pillar Data Systems this week finally launched itself and its first product—the Axiom disk array. To date, Pillar has been known primarily as Oracle CEO Larry Ellison's storage company. Ellison's Tako Ventures, which is part of Lawrence Investments, has invested about $150 million in Pillar, making it the most well-financed storage start-up ever.
Although the $150 million in venture funding gives Pillar a leg up on other start-ups that are trying to steal a piece of the pie from vendors such as EMC and Network Appliance, the start-up's success now depends on the Axiom system, which combines a number of technologies that individually aren't unique but taken together may prove appealing to end users that are open to buying large disk arrays from start-ups, according to analysts.
In a nutshell, some of the key features of the Axiom system include the following:
- Combined NAS and SAN in a single system;
- Multiple storage tiers at the disk level;
- Policy-based, application-specific quality of service (QoS) levels;
- Relatively easy management; and
- Relatively low cost versus market share leaders.
The Axiom array can be configured as NAS only, SAN only, or a combination of NAS and SAN, according to application requirements under a common management interface. This approach, which Pillar refers to as "peered, or native, NAS and SAN," differs from other approaches that put a NAS gateway in front of a SAN or approaches that layer software on a NAS filer to provide SAN functionality.
Initial shipments (which began this week) only include support for NAS. Support for SAN is scheduled for late next month, according to Mike Workman, Pillar's president and CEO, who was formerly with IBM's storage technology division.
"Pillar's back-end NAS/SAN management is cleaner than with vendors that started out with NAS and added SAN later," says Arun Taneja, a consulting analyst and founder of the Taneja Group, "but that's the advantage of being late to market—they were able to start from scratch on the NAS/SAN support."
QoS on disk
Although Pillar touts a single-system tiered storage architecture, it differs from other vendors' implementations. For example, many vendors offer in-box tiered storage via the ability of users to mix-and-match high-performance, high-cost Fibre Channel drives and low-cost, high-capacity Serial ATA (SATA) drives to create storage tiers according to cost/performance requirements. In contrast, Pillar's Axiom is currently available only with SATA drives (although Fibre Channel drives will be available in a future implementation expected late this year or early next year).
To provide storage tiers and multiple levels of service (QoS) from a single storage pool, the Axiom system enables administrators to control the placement of data on individual disk drives according to application performance requirements. For example, data for database applications that require high performance can be placed near the outer diameter of the disk platters (where the data rate is highest), while lower-priority/performance data can be automatically stored on the inner tracks of disks. Archive data, for example, would typically be stored on the innermost tracks. Policy-based data placement is controlled via rules-based management software.
Although this technique ("intelligent data placement") is not unique (it has been used in the mainframe storage space, as well as a few other systems), Pillar couples the following technologies with user-specified data placement: priority queues, caching algorithms, spindle striping levels, and mirroring to tune QoS requirements in the tiered architecture.
"Pillar gives you multiple tiers of storage by placing data at different locations on disk so that in some cases you may be able to get Fibre Channel performance out of SATA disks," says Taneja. "In other words, you can have multiple tiers of storage on a single disk drive."
An Axiom system consists of a number of modular building blocks, including Pilot policy controllers (which run the management software and handle tasks such as virtualization mappings, QoS policy management, predictive modeling, snapshots, volume copies, etc.), Slammer storage controllers (which manage NAS and SAN I/O, including I/O prioritization/allocation, cache prioritization, load balancing, etc.), and up to 32 RAID-based Brick storage enclosures (see "Axiom at-a-glance" below). Each system scales from 3TB to 300TB. The management software allows administrators to allocate storage resources, set application-specific QoS profiles, and define task automation parameters such as data replication schedules.
"The modularity enables you grow, or scale, independently along three dimensions: I/O, throughput, and capacity," says Taneja.
Although it remains to be seen how the performance of an Axiom array stacks up against other NAS or SAN arrays, Pillar has loaded the system with a lot of processors and cache. For example, each Slammer controller includes up to four processors, which can be scaled to four Slammers for a total of 16 processors. And a single active-active Slammer controller supports up to 24GB of cache memory, which can be scaled to 96GB of cache per array.
External connections include 2Gbps Fibre Channel and Gigabit Ethernet (although the system does not currently support iSCSI).
Pricing ranges from $50,000 to $500,000 per Axiom system.
Headquartered in San Jose, CA, Pillar has approximately 325 employees. The company claims to have about 150 customers in the beta program, including companies such as Nielsen Media Research, LeapFrog, Xerox, and eHealth Insurance. Pillar is primarily targeting Global 5000 companies, or those with more than $100 million in revenue, according to Workman.
"Slammer" storage controller
- Dual active control units—complete HA
- SAN or NAS option
- Four Pentium 4 Xeon processors
- Up to 24GB RAM
- Up to 8GB NVRAM (battery-backed)
- Four GbE ports or four 2Gbps FC ports
- Dual embedded FC switching to Bricks
"Brick" storage enclosure
- Dual active RAID controllers
- Embedded RAID 5
- FC interface to SATA or 15K FC drives
- Hot-swappable drives, RAID controllers, and
"Pilot" management controller
- Dual control units
- Active-passive—high availability
- Two Pentium 4 processors
- Two hard drives for configuration and logging
- Six 10/100/1000 Base-T Ethernet