Quantum DLT-V4 tape drive
By Dave Mitchell | Techworld | Published: 09:00, 07 February 2006
Competition in the mid-range backup market may have settled down now with LTO taking the lions share over SDLT but at the entry-level things are really starting to heat up. There are plenty of formats vying to take a slice out of the huge territory once commanded by DDS and Quantums latest DLT-V4 introduces the third generation of its ValueSmart (VS) family.
The VS format has been in existence for over six years now so its well established although in its early days it did suffer from a snails pace development. Introduced back in 1999, the original DLT1 format was offered by its inventors Benchmark Systems as a budget priced backup solution that cost the same as DDS-4 but offered better far performance. The format was re-branded as the VS80 which delivered the same package in a half-height form factor making it a good choice for entry-level server backup as it could be bundled as an internal drive. The second generation VS-160 didnt appear until early 2003 and by then Quantum had acquired Benchmark.
Quantum has clearly spurred development on at a faster space as we havent had to wait quite so long for the third generation. As we would expect to see, native capacity has been doubled to 160GB and its interesting to note that the DLT-V4 uses the same cartridges as the VS-160 so media costs havent increased. However, its disappointing to see performance only getting a 25 per cent boost to 10MB/sec. We asked Quantum why it hadnt delivered the usual doubling in performance and it advised us that its key priority was to increase capacity. Quantum has seen the value of the Serial ATA (SATA) interface and along with the external Ultra160 SCSI version on review it also offers an internal SATA/150 model as well. This is a sensible move as the majority of entry-level server motherboards come with embedded SATA interfaces as standard allowing you to implement the drive without having to cough up for an extra adapter card.
A key feature of the DLT-V4 is support for Quantums DLTice which is provided as part of its DLTSage xTalk tape diagnostics toolbox. To comply with data protection and archiving regulations it writes a unique tamper-proof electronic key to the tape which ensures that it is now non-erasable and non-rewriteable. You can append data but the tape contents cannot be altered or the tape reformatted. Another advantage is you can use standard VS1 tapes for WORM (write once read many) duties. As DLTIce is implemented in firmware the drive needs the latest version applied but xTalk will check the drive, download the latest version and apply it for you. The process of turning a tape into WORM media is simple as you load a cartridge and select the DLTIce option which writes the key to the tape.
For speed tests we hooked the drive up to dual Xeon Supermicro rack server running Windows Server 2003 and loaded it with Computer Associates ARCserve r11.5 and Symantecs Backup Exec 10d. With 9GB of test data on the server we asked the software to secure it, verify the tape contents and restore it back to its original location. For each respective test ARCserve returned 11.7MB/sec, 12.4MB/sec and 10.8MB/sec whilst Backup Exec reported 11.7MB/sec, 12.2MB/sec and 11MB/sec for the same tasks. We also had no problems converting a tape to WORM media using the xTalk utility. ARCserve recognised the blank WORM tape and allowed us to format it and then write to it but if you attempt to format the media a second time it will stop you with a warning message advising that data is present.
As a DDS replacement the DLT-V4 looks a top candidate as it delivers a far superior performance and capacity at a price that compares very well with the competition. Users looking to upgrade from DDS-4 to DAT72 may also want to reconsider as this format only offers a pedestrian 3MB/sec native performance and a paltry 36GB capacity on compact 4mm cartridges. However, our sources tell us that HP will be launching a DAT160 tape drive very soon although no details are yet available about what performance improvements can be expected. Sonys AIT (advanced intelligent tape) is another contender but the company did commit a major screw-up in 2005 when it had to withdraw backward compatibility claims for the AIT-4 format. Theres also Exabytes VXA format which is now on its third generation with VXA-320. At 12MB/sec it is slightly faster for native operations and the 8mm cartridges also offer a 160GB native capacity.
The DLV-V4 looks a very solid platform for backup operations in the SMB (small medium business) environment. It clearly delivers on the quoted performance and a clincher over many competing formats is support for Quantums DLTice allowing the cartridges to be used for regulation compliant data archiving.