Raidtec FibreArray and Raidtec FlexArray UltraRAID Systems

I'm always looking for bigger, faster storage systems because I frequently run out of room on my system, and I often come across new applications that need better disk performance than I have. Raidtec offers two storage systems that address both of my needs:

• The FibreArray, a Fibre Channel Arbitrated Loop (FC-AL) disk subsystem with RAID capabilities (if you have Windows NT)

• The FlexArray UltraRAID, a dual-channel UltraWide SCSI-3 RAID disk subsystem

(For more information on the differences between fibre channel and SCSI systems, see my article "Fibre Channel, SCSI, and You," September 1997.)

Each disk subsystem comes with an enclosure, hard drives, a controller card, cables, and software. The enclosure is a fault-tolerant tower configuration with room for seven industry-standard, bus-isolated, hot-swappable hard drives. It also uses redundant, hot-swappable fans and power supplies to make it even more resilient. The enclosure sits on lockable wheels. It is 17.4 inches tall, 8.7 inches wide, and 20.6 inches deep and weighs about 45 pounds without the hard drives installed. Raidtec makes a rack mountable version, or you can purchase a rack mounting kit and convert the tower system to a rack mounted system later.

An Environment Array Manager (EAM) is built into the enclosure. EAM monitors the status of the drive bays, power, fans, and internal temperature. It also controls the built-in LCD display and the light-emitting diodes that indicate the status of each drive. A four-button touch panel with an LCD status display is conveniently located on the front of the unit.

You can chain multiple enclosures of the same type (SCSI or FC-AL) together and manage them with the RAIDman LITE software, which is included. The software lets you monitor and perform diagnostics on a given hard drive or the entire enclosure. You can even perform these tasks from a remote workstation.

Adding Fibre to my Diet
The FibreArray FC-AL disk subsystem that I reviewed used an Emulex LightPulse PCI Fibre Channel Adapter connected to the FibreArray fault-tolerant drive enclosure. (For information about the adapter, see "Emulex LightPulse PCI Fibre Channel Adapter.") The enclosure was loaded with seven Seagate 9GB fibre channel hard drives, giving a total of 63GB of storage space within one cabinet. You can chain 16 FibreArray enclosures together, which lets you have 112 drives online at once. This setup will give you more than 1TB of online storage.

The FibreArray disk subsystem achieves data rates of 106MB per second. You can double this rate by adding a second port bypass module. You can connect the subsystem to any FC-AL compliant controller. FC-AL lets you connect up to 126 devices in a single loop and string them up to 98.5 feet apart. Alternatively, you can use optical cable to string the devices as far as 6.2 miles apart.

Setting up the FibreArray disk subsystem was easy. I installed the Emulex adapter in the server, connected the FibreArray to the adapter, booted the server, and installed the Emulex adapter drivers. To complete the setup, I used NT's Disk Administrator to format the hard drives.

I performed several tests on this system. Not only was FibreArray easy to use, it was also fast and effective. I did, however, find one drawback: To get RAID capabilities, you must use the RAID software that is built into NT. This is a disadvantage compared to hardware-based RAID solutions. But Raidtec is correcting this situation by releasing the Raidtec Fibre RAID-PCI controller this month.

My SCSI Story
The FlexArray UltraRAID disk subsystem I reviewed included the FlexArray fault-tolerant drive enclosure, the Raidtec UltraRAID controller, and seven Seagate 2GB UltraWide SCSI-3 hard drives. The enclosure supports off-the-shelf standard SCSI disk drives. You can connect two enclosures together to the UltraRAID for improved manageability and increased online storage. The largest drives that you can install are 9GB drives, so you can get a total of 63GB of online storage with one enclosure and 126GB with dual enclosures. You can install any industry-standard Single Architect Drive in this subsystem.

The RUAC RAID controller is a PCI card with two ultrawide SCSI-3 connectors and a serial connector for configuration and monitoring. It uses two card slots and has an Intel i960 processor and a SIMM socket for cache RAM. The controller also has an onboard parity generator that calculates parity data on the fly, boosting performance over other RAID controllers.

The FlexArray disk subsystem was as easy to install and use as the FibreArray disk subsystem. I installed the RUAC RAID controller, connected it to the FlexArray, booted the server, and installed the RAID controller drivers. I then configured the drives using Raidtec's RAID configuration software. The configuration software is a DOS-style utility that works reasonably well. After I partitioned the drives using the configuration software, I used NT's Disk Administrator to format the partitions.

Which One?
Both of these systems are definitely worth investigating because of their high performance, ease-of-configuration, diagnostic functions, and fault-tolerance abilities. The FlexArray UltraRAID is worth considering if you are on a budget and don't need the flexibility that fibre channel offers. If you need the fastest system possible or the flexibility of fibre channel, the FibreArray is a better choice.