Tape may still be the best choice for backing up large amounts of data but for the single user and small business it’s not often the most cost-effective option as the tape drives can be prohibitively expensive. An increasingly popular alternative is disk to disk (D2D) backup as high capacity hard disks offer good levels of storage, superior performance and cost a lot less than most small business tape drives.
The latest Data Express DX115 from StorCase aims to deliver a low-cost D2D solution but also brings into play simple hot-swap capabilities. Portability has always been a strong point of tape but with this in the StorCase equation disks become just as versatile. The product is offered in two versions and features are determined purely by the version of EMC Retrospect you select. On review is the single user PC backup version bundled with Retrospect Express which supports a single non-server Windows system. Alternatively, you can go for the one with Retrospect Disk-To-Disk which allows a Windows server to be backed up.
The kit on review comprises a well built frame which slots neatly into a standard 5.25in bay. It has an integral cooling fan and at the rear are a single SATA interface and SATA power connection. At the front are indicators showing drive status and activity plus fan failure and a small button below is provided for controlling power to the drive.
The drive caddy is very solid and we were supplied with one fitted with an 80GB Seagate Barracuda SATA/3Gbps hard disk. Along with this we were provided with a second caddy with another 80GB drive installed. Usefully, the installed caddy can be key-locked in the frame to thwart wandering fingers. A key feature of the frame is its ‘Soft-Start’ circuitry which improves drive longevity by negating any power arcing when drives are inserted and provides a smooth supply to drives when they spin up.
Physical installation is easy enough although bear in mind that the frame is quite deep and will need a fair amount of clearance at the rear. For hot-swap functions you get a copy of DriveSwap32 which automatically identifies the StorCase hard disk and displays it ready for selection. Just tick the box alongside, hit the Remove Drive button and the software will soft lock the drive and make it ready for removal. The caddy can then be powered off via the button on the frame and safely removed. Drive insertion is just as easy as you slip the drive in and power it up. It is annoying that each time Windows will see it as new hardware but drivers are loaded automatically and it only takes a couple of seconds anyway. Another bonus is the drive appears natively so is assigned a drive letter allowing it to be accessed by pretty much any application you want.
For backup operations Retrospect is easy enough to use and packed with plenty of wizards. However, note that the version supplied is the earlier v7.0 as EMC doesn’t offer an Express version in its latest v7.5 release. This is no real issue though as all additional features in the later version are aimed at network backup anyway. Furthermore, although Express is aimed at hard disk backup it does also allow you to use locally attached CD/DVD-RW drives as well.
Backup operations only take a few minutes to set up using the wizard and you start by selecting source files which can be local and on a mapped network drive. Next, you choose the DX115 as a destination, run the job manually or create a daily schedule and decide whether to use multiple backup sets which adds another layer of protection by creating extra backups. Opting for two backup sets allows you to alternate them each week whilst seven means you can use a different one for each day of the week.
Note that Retrospect takes an unconventional approach to backup as it doesn’t use a file’s archive bit but compares the files it has already copied with those on the hard disk and if the exact same file already exists on the backup media, it will not be copied again. Compression can also be applied to each set to reduce space usage and useful features if you’re storing your drives off-site is the option to password protect and encrypt the data as well. There’s more as Retrospect keeps an eye on the capacity of the destination drive and can remove older backup sets as it fills up.
For testing we installed the DX115 on a 3.2GHz Pentium D PC equipped with 1GB of PC5400 memory and running Windows XP SP2. We found overall performance to be very good and far superior to an equivalent low-end tape drive. For raw performance we used Iometer configured with 256KB transfer requests and 100 per cent sequential read operations and it reported a speedy 55MB/sec. Real world write performance was good as well with a 1.62GB disk image copied to the DX115 in a mere 36 seconds for an average of 46.1MB/sec.
Retrospect posted impressive speeds as well with an uncompressed backup of 5GB of test data returning an average of 30.4MB/sec – that’s faster than an Ultrium LTO-2 tape drive. Software compression reduced the amount of space used by seven per cent but expect a hit on performance as the same job with this option selected dropped speed to 16.1MB/sec.
On performance alone the DX115 delivers the goods - check out the latest DAT72 tape drives as an outlay in excess of £350 will get you get a paltry 3.2MB/sec. Add in the Retrospect Express features and ease of use plus the hot-swap capabilities and you have a simple, cost effective D2D backup solution.
D2D backup for single users has traditionally been problematic due to the lack of solutions that support hot-swapping of hard disk media. The StorCase DX115 solves this neatly with a simple solution for swift removal of backup media and the partnership with Retrospect returns extremely good performance