Ease Software's Hard Disk Storage for AIX

The Disk Solutions offered by Ease Software are based upon state of the art Serial ATA (SATA) technology. You can read about the advantages of a serial interface here. SATA is a disk interface technology developed for the PC market and is used in today's PC's and Mac systems. The disk drives, cables, cabinets, and adapters are all very high volume. As explained here, SATA is inherently simpler and smaller. These factors combine to produce extremely low cost components.

Ease Software takes advantages of the high volume, low cost components and is able to provide complete disk solutions for $2 per gigabyte in most instances. For example, the one terabyte disk system which sells for $1999, includes

  • host bus adapter (HBA)
  • five bay hot swappable disk cabinet
  • 1.5m external SATA cable
  • two Seagate Barracuda ES 500G drives
This leaves three disk bays available for even lower cost expansion.

The Seagate Barracuda ES drives are Seagate's newest and highest performance drives. Seagate is a well recognized name in the industry and has been a key participant in the development and specification of the SATA interface. These drives feature:

The hard drives in our disk systems appear as normal hdisk drives to AIX's Config Manager and Logical Volume Manager. They can be grouped into volume groups and then split back apart into logical volumes just as native hard drives can.

Our tests show a throughput of 250 megabytes per second when we set up a five disk striped logical volume over a single SATA port connected to a two-way p5-520 AIX server running Virtual I/O server.

The Silicon Image SiI3124-2 controller supplies four SATA ports. We offer two versions of the adapter: one with internal SATA connectors and the other with external eSATA connectors. Each port operates at three gigabit per second. The adapter uses the newer faster 64 bit PCI-X interface offered in the new IBM p5 systems.

The five bay disk cabinets we offer are produced by Silicon Image and incorporate their SiI4726 five drive port multiplier. This allows a single SATA port from the HBA to control up to five disk drives.

The hard drives in the disk towers are hot swappable. This means that they can be removed and replaced while the system is still running. This opens the door to using SATA hard disks as back up media. Compare speed and prices with any tape solution and you will find that SATA hard drives are very price competitive and offer all the advantages of the random access nature of disks over the serially accessed nature of tapes.

By using Seagate 750G drives, a fully configured SATA host bus adapter can access fifteen terabytes of storage. A single AIX system can have multipler SATA HBA's installed at the same time providing 15TB for each available PCI or PCI-X slot. For example, an AIX server with four available PCI slots could access 60TB of data.