Scalar 1000

An expandable robotic tape library for enterprise-level backups

The Scalar 1000 from Advanced Digital Information Corporation (ADIC) is an expandable robotic tape library designed to handle enterprise-level backups. The base unit, which ADIC calls the Control Module, can handle DLT, AIT, or IBM 3590 drives. Depending on the type and number of drives installed, the Scalar 1000 can accommodate 3.5TB to 23.7TB of compressed data. In addition, you can bolt as many as three Expansion Modules to the Control Module to boost storage capacity to a maximum of 118.2TB.

I reviewed a DLT version of the Scalar 1000 that had four DLT7000 tape drives and 158 slots, providing 11.1TB of storage capacity. In my test, I populated only 29 of the available 158 slots with DLT tapes. The Scalar 1000 uses a SCSI-2 differential interface; single-ended SCSI isn't an option.

The Scalar 1000 requires a special twist-lock power cord, so an electrician had to modify a standard 110-volt outlet before I could begin testing. An ADIC technician and I then hooked up the differential SCSI cables from our test server to the tape drives. We used two SCSI host adapters in our server and connected each adapter to two drives, then daisy-chained the robotics control off one set of the drives. The product's cabinet provides plenty of room for connecting and routing cables.

After I switched on the power, the Scalar 1000 immediately performed a power-on self test. The Scalar 1000 then initiated a learn sequence to establish the correct X- and Y-axis coordinates of the drives and tape slots. This process sent the robotic gripper to scan a narrow barcode label on the face of each tape slot and drive. To prevent injury, the Scalar 1000 includes a safety switch that powers off the robot if someone opens the enclosure door. If you unlock and open the door before you park the gripper, it will drop from its vertical traverse, potentially damaging the barcode reader.

After the product completed the self-test and learn sequence, I learned the LCD display's menu options. The keypad isn't intuitive, but within a few minutes I could navigate through most of the menu options and perform simple tasks. A Help button provides context-sensitive Help text on the LCD display, and the operation manuals provide more detailed information. After I became familiar with the controls, I ran a demo cycle to watch the gripper work.

ADIC claims that the Scalar 1000 mounts media in 6 seconds or less. I timed gripper actions, and no mount took more than 4 seconds. In the infrequent instances when the initial tape load failed, the gripper detected the aborted tape load and gently pushed the tape into place until the tape loaded.

When you add Expansion Modules, the Scalar 1000 extends the horizontal rails that define the gripper's X-axis. This extended axis lets the robot traverse the entire width of the library. Therefore, the Scalar 1000 maintains less than 6-second tape-mount times regardless of how many Expansion Modules you add.

I used the Scalar 1000 as part of the test bed for "Enterprise Backup Software," page 135. For that review, I backed up more than 7TB of data and issued hundreds of mount and dismount requests. The Scalar 1000 performed well throughout the testing, and I encountered only two problems. First, the product claimed that something was obstructing a path to one of the drives. The drive bay wasn't obstructed, so I initiated a learn sequence from the keypad. In about 2 minutes, the Scalar 1000 relearned its X and Y coordinates and came back online. The second problem arose when one of the DLT drives failed. ADIC shipped a new drive, and I changed out the drive in about 10 minutes.

I was happy with the Scalar 1000's performance. It was reliable, fast, and easy to use. I also had a good experience working with the ADIC technicians. The Scalar 1000's performance and expandability, backed by a good technical support staff, make this library an excellent choice for organizations that predict growing data storage needs in the next several years.