The Exabyte 218 4mm Tape Library, our best-overall 4-mm choice (see the article "Tape Libraries Ratings"), dispels the commonly held belief that 4-mm tape libraries are merely entry-level backup solutions. With its voluminous 152-GB storage capacity, this dual-drive-configured tape auto-loader can back up multiserver networks.
The tape library rated closest to the Exabyte unit in this category is ADIC's VLS 4mm, a dual-drive desktop system with a 120-GB data capacity.
This dual-drive capacity lets you retrieve files on one drive while backups are running on the other drive. The VLS 4mm received one of the highest usability ratings because its removable, 15-cartridge FastPort magazine is easy to load and unload; it has a clear and concise user's manual; and its status indicators are easy to understand.
HP's SureStore 12000e and Micro Design International's SCSI Express 2000DC are two strong, compact DAT tape libraries with 48-GB capacities. They both have HP-manufactured drives and thus have similar performance numbers. They are supported by leading network-backup applications vendors, such as Cheyenne Software and Seagate Software (formerly Arcada and Palindrome). The only inconvenience with these smaller drives is that you can't see if a tape is stuck inside the loader; however, the HP tape library has an informative LCD panel that keeps you abreast of what's going on.
DLT Choices
The DLT market is really heating up. Currently DLT tape drive
s account for about 7 percent of the tape-library market, but industry analysts predict that number will surge to 26 percent by the turn of the century. HP, one of the market leaders in DAT tape storage, recently threw its hat into the DLT arena and offered its first DLT-based products. Unfortunately, however, we didn't receive a product in time for this roundup. It looks like DLT is a technology worth keeping an eye on.
Overland Data's DLT Library Xpress/LXB 2210 is our best-overall choice among the DLT tape libraries because of its strong features and ease of use. Like Overland's unit, Quantum's DLT 2500XT and ADIC's Scalar 458 2000XT use Quantum-manufactured drives that afford the best performance among the three media types we tested. Because these DLT tape libraries have similar performance numbers, the choice comes down to how much network data you need to back up.
The ADIC Scalar 458 2000XT ($50,995) is the most expensive tape library that we tested, but it has four tape drives and offers t
he greatest capacity, with almost 4 TB of total storage in its huge 58-cartridge cabinet. At $4995, the Quantum DLT 2500XT is a much more modestly priced mini-library, with five cartridges for 150 GB of backup. Quantum's desktop device uses an elevator mechanism to provide cartridge access between the tape drive and the cartridge magazine, while the other DLT drives use robotic cartridge handlers.
8-mm Choices
The two 8-mm tape libraries in our roundup are huge, freestanding units that support enterprise-wide backup needs. Both use Exabyte-manufactured tape drives, so their performance in our backup and restore benchmarks were almost identical. The Exabyte 210 8mm Tape Library ($13,325) came out slightly ahead of Qualstar's TLS-4220 because of its higher usability and features scores.
However, the Qualstar TLS-4220 ($12,500) has several advantages over Exabyte's product in a head-to-head comparison. The TLS-4220 holds 20 cartridges, compared to 11 cartridges for Exabyte's 210 8m
m. The TLS-4220 also offers great expandability options. It's only the third member of Qualstar's wide-ranging TLS-4000 product family. Therefore, if your data-storage needs expand, you can upgrade to Qualstar's TLS-46120, a monster of a tape library that has six drives and 120 cartridges, for over 1.6 TB of backup. The TLS-4220 has an intuitive control panel, and you can lock the cartridges inside the case for data security.
DLT
-- One of the hottest technologies in the tape-backup industry.
-- 40-GB-per-cartridge compressed capacity.
-- Serpentine recording technique places data in longitudinal
tracks for high-speed backup and restore performance.
-- 30-year shelf life is ideal for archiving data.
4 mm
-- An older helical-scan technology, where tape is laid down in angles.
-- Smallest form factor of the three technologies.
-- Native capacities of 2 GB or 4 GB.
-- The latest DDS-2 format
provides double density.
-- Stores 8 GB of data on a 120-meter tape.
-- Not as fast as DLT but offers exceptional cost per megabyte.
8 mm
-- Another helical-scan technology that offers an excellent price/
performance ratio.
-- 8-GB native capacity and 16 GB with 2:1 compression.
-- Offers performance similar to that of 4-mm drives.
-- Technology will get a performance/capacity boost when Exabyte's
40-GB, 6-MBps Mammoth tape drives filter to OEMs.
Tape Libraries
