Dell tape library is built to scale

Tape libraries recently experienced a dramatic evolution, changing from monolithic brontosaurs that you had to carefully size according to present and future demands, into more congenial devices, easily scalable for capacity and performance.

This new breed of modular, scalable library also has a gentler impact on your budget and on your asset depreciation. Basic module library models are often only slightly more expensive than some autoloaders, which makes them attractive to a larger audience.

In December, Dell added another backup solution to its portfolio and began shipping the PowerVault ML6000, a new modular library based on the ADIC Scalar i500 that promises easy updates to add capacity and performance, as well as friendly management tools. After testing the ML6000 at Dell's Austin, Texas labs, I'd say it delivers on that promise very well.

A Bigger Screen is Better

The first thing I noticed on the ML6000 evaluation unit was the library's wide, touchscreen control panel. The screen is about 3.5" wide and 6" tall, giving it a rather comfortable feeling that other skimpier sized control panels -- such as the one mounted on the Quantum PX500 -- do not evoke.

In addition to improved readability, the ML6000's larger control panel has the same menu structure and screens content as the library's browser-based management application, so your operators will have to familiarize themselves with just one interface.

Although the HTTP GUI doesn’t have all the content found on the library panel -- you can access more diagnostic screens from the latter, for example -- the differences are minimal and I was equally comfortable working from the library touchscreen or from the HTTP GUI.  

My test library mounted two SCSI LTO-3 (linear tape open) drives from IBM and had room for 128 cartridges (FC drives are also available if  you have a fibre network), all of which you can easily find by browsing the management GUI.  Another UI screen showed a summary view of all the drives, data, and service slots, and had the option of showing either the location or the barcode of each cartridge.

The GUI also has numerous wizards to simplify installation tasks, such as partitioning the library into separate sub-libraries, permanently assigning certain slots to cleaning cartridges, and saving or restoring a configuration.

Diagnostic activities include updating the firmware and exporting log files to a local drive for further analysis, both of which worked well in my testing. My test environment was not set up to review the ML6000's other diagnostic features, such as e-mail notifications for major events or calling home when a fault is predicted, but I was satisfied with the  management tools I saw and used.

The Backup-Restore Shuffle

Judging from the management screen I could have been working with one of those brontosaurs mentioned before: my library was made of two modules, a 5U segment hosting drives and robotics and a 9U expansion unit, which tacked on a possible 92 additional cartridge slots. This was as far as the ML6000 could scale at the time of my review, which is not bad, but Dell is working on some firmware adjustments that should allow you to add more expansion modules.

There was no additional drive on the system I tested, but the expansion module can host more slots and improve performance with four more LTO-3 tape drives. Mounting other tape drives, such as Quantum's DLT (digital linear tape), is a possibility that Dell will consider if there is a demand, I am told.

Doing backups and restores is about as exciting as watching paint dry -- and should stay that way, because excitement is the last thing you want when protecting your data. Of course, a data error or a tape jam can fill a boring and reassuring backup session with fingernail-biting apprehension, but none of that happened during my tests with the ML6000. My Windows backup server had the latest version of Symantec Backup Exec already installed, but the library works with a variety of backup applications that should meet most customers' demands.

Working on a single tape and with a dedicated server, I measured between 60 and 76MBps for both backups and restores. Depending on your environment, you could get closer to the 80MBps max data rate of the IBM tape drive; multiply that by the maximum six drives supported by ML6000 and you have a good amount of data crunching power for your backups.

I can't find much to critique after my evaluation of the ML6000: it's a solid, easy to manage system. The library is based on ADIC technology and on the speedy LTO-3 tapes from IBM, and Dell bundles in a reassuring three-year warranty.  The ML6000 doesn't currently do data encryption, so if encryption is a priority you may want to consider other options or wait until the LTO triad's (HP, IBM, and Quantum) efforts to provide native encryption trickle down to this product.

Otherwise, the Dell PowerVault ML6000 is an affordable, ready-to-grow library that should facilitate moving up from autoloaders or older, maxed-out models. It's certainly worth considering if LTO tapes are your cup of tea.