In the computer industry, flexibility is imperative. The ability to configure your storage space in a changing environment is a necessity. Most storage products let you configure storage space a few ways, but Storage Computer's OmniRAID Cluster Array lets you configure storage space in almost any environment.
With the OmniRAID Cluster Array, you can partition storage space onto two or more disks with nonconcurrent access from multiple hosts. You can configure the disks into one large hard disk with concurrent access from multiple hosts. However, until a distributed lock manager is available for Windows NT, this configuration won't work. You can also partition the space onto two hard disks with concurrent access from two hosts, which is what I did for my tests in the Windows NT Magazine Lab. To conduct clustering tests, I needed to connect two identical hard disk partitions with two SCSI host adapters from each host into the rear panel of the OmniRAID Cluster Array.
Configuring the System
To configure the OmniRAID Cluster Array, you need to set up a configuration disk. You must boot up the OmniRAID Cluster Array using this disk each time you use the array. You must also configure the OmniRAID Cluster Array cabinet. The OmniRAID Cluster Array cabinet relieves the storage space problem all networks experience and provides the data protection all networks need. The user's manual outlines these configuration procedures. However, I would have preferred to have a wizard walk me through each step.
OmniRAID Cluster Array uses RAID 7, a more advanced version of the independent access array (RAID levels 4, 5, and 6) concept that assists in data throughput. RAID 7 is an asynchronous access level that, like RAID 4 and RAID 5, uses a singular parity stripe to protect data stored across multiple data stripes within the same data transfer. RAID 7 alleviates the write bottleneck that characterizes RAID 4 and RAID 5. In addition, each member of a RAID 7 array has a dedicated channel of memory and CPU resources, resulting in faster I/O.
Setting Up the System
To set up the OmniRAID Cluster Array, I ran the RAID 7 diagnostic disk, which tests all system components. Next, I inserted the RAID 7 Storage Operating System (SOS) disk and rebooted the cabinet. The product performs a physical resource audit that it writes to the SOS disk. When the audit is complete, the system writes a configuration file that specifies the number of drive and host channels and the amount of available disk space. I removed the SOS disk and inserted the RAID 7 configuration disk. At the appropriate prompt, I reinserted the SOS disk and the Main Configuration menu appeared. This DOS-based menu doesn't offer online help. However, the user's manual provides explanations for the various menu parameters. I used the configuration program to set two partitions and their controlling host channel numbers, SCSI target ID numbers, and Logical Unit Numbers (LUNs). I wrote the configuration to the bootup disk and kept a backup copy.
I rebooted the cabinet with the SOS disk, and my parity drive started its creation process. When this process ended several hours later, the OmniRAID Cluster Array operated like a SCSI drive. I connected the ends of two SCSI cables to the Host 1 and Host 2 connectors inside the cabinet and the other ends to Adaptec 2940UW SCSI adapters in my test computer. After I rebooted the computer, I configured the adapters, rebooted again, and logged on to NT. I opened the Disk Administrator, and my two 67.831GB partitions were ready for formatting. After I formatted the partitions, I copied data to them, and they operated like RAID drives.
You can connect the OmniRAID Cluster Array to four host computers or channels simultaneously. The OmniRAID Cluster Array can also expand to support as many as twenty-seven 9GB hard disks. An i486DX2-66 processor with 2MB of RAM controls the OmniRAID Cluster Array's overall operation. The OmniRAID Cluster Array's redundant power supplies let the system continue when one of the power supplies fails. The configuration and use of the OmniRAID Cluster Array is almost limitless, although the cabinet's size (78" * 24" * 36") might limit where you can put it. (The system is available in various sizes and configuration capacities. You can also adjust the number of host connections.)
I used Iometer to test my newly created drives and OmniRAID Cluster Array controllers. Iometer provides disk I/O subsystem measurement and characterization for simulated users (workers) operating a particular system (i.e., single or clustered). Iometer calculated the I/O per second and the average and maximum response times in milliseconds (ms) for the OmniRAID Cluster Array. (You can download Iometer for free from Intel's Web site at http://developer.intel.com/design/servers/devtools/iometer.)
I chose a 30-minute test with one worker generating the load. The test completed in approximately 35 minutes. The I/O per second was 58.22, and the average and maximum response times were 9.2ms and 38.45ms, respectively. I ran the test four times, and each time the results were within 1 percent of the original results.
A Worthy Storage Solution
The configuration process for the OmniRAID Cluster Array is not as quick as other RAID arrays the Lab has tested, but it is just as thorough. Despite initial difficulties with the bad drive and array board, the OmniRAID Cluster Array worked well (although a GUI tool to ease navigation would have been helpful). The OmniRAID Cluster Array's RAID 7 technology offers additional data protection and increased storage space, and the system's four-host expandability makes it a worthy storage solution.
|OmniRAID Cluster Array|
| Contact: Storage Computer * 603-880-3005|
Price: Starts at $105,260
Host 1: Dual 200MHz Pentium processors, 128MB of RAM, 4GB hard disk, Two Adaptec 2940UW SCSI adapters
Host 2: 166MHz Multimedia Extensions Pentium processor, 96MB of RAM, 3.1GB hard disk, Two Adaptec 2940UW SCSI adapters