Two versions of Iomega’s latest assault on the removable storage market, the REV, have been released so far, an external USB 2.0 model and an internal ATAPI. The USB 2.0 model isn’t host-powered, which is a shame but at least the transformer is tiny, not much larger than a couple of matchboxes. The REV Removable Rigid Disk (RRD) cartridge is quite dinky, measuring just 75x77x10mm and weighs a mere 73gms. Iomega believes that the REV disk to be the smallest portable storage disk in the marketplace to hold 35GB of data.

Iomega’s previous removable hard disk range, Peerless, was based on conventional off-the-shelf 2.5-in hard disk drives. This approach has been abandoned in the new Iomega Rev, which marks a return to the removable cartridge concept used in its somewhat less than reliable Jaz drives, but with a big difference. Gremlins in the form of minute debris were the cause of many a problem with the Jaz cartridge, was which simply too ‘leaky’ for its own good. The new REV does not ‘leak’.

The new REV RRD still has an external, drive-mounted, head mechanism but the disc motor has now been brought on board. Considerable attention has been devoted to ensuring that REV cartridges are either virtually air-tight or offer higher-pressure than the drive bay, so ensuring that any flow of air is outward and not inward. For example, the shutter on the drive and the shutter on the cartridge open in tandem, so the sealed environments of the read/write heads remain clean inside the drive. They also get cleaned automatically. An air filtration system emulates the clean environment of a conventional hard drive. Iomega is quite bullish about the resulting reliability of REV – it has a read/write specification of 1 million rewrites, with a mean time between failures (MTBF) rating of 400,000 hours, which compares very favourably with tape. Iomega expects REV to provide comparable reliability to today’s sealed hard drives in a more convenient and versatile removable form factor.

REV RRD’s have a 7,200rpm spindle speed, with a 13ms average access time which isn’t too bad by modern standards, given that the REV is removable storage. The maximum theoretical transfer rate for REV drives is 24.5MB/sec, although this transfer rate does change as the heads move from the outside diameter of the disk to the inside, dropping from 24.5MB/sec at the outside to 12.7MB/sec at the inside.

Sadly, the current supported interfaces, USB 2.0 and ATAPI don’t really do the REV justice – you get as little as 15MBsec out of USB 2.0. Using drag and drop file copying, to copy 18,900 files amounting to 686MB, I was lucky to get 1.5MB/sec on a variety of USB 2.0 interfaces, which is very disappointing. Copying a single, 272MB file proved significantly faster, about 6MB/sec but still well short of expectations. We’re going to have to wait for the release of the Pro version later this year for fast interfaces: SATA, SCSI and host-powered FireWire for the Mac market.

At £280 the 35GB REV is expensive as external storage goes – you could buy a trio of LaCie 80GB external USB 2.0 drives for £225 and still have change for a very agreeable lunch. And that presumably is why Iomega is positioning the REV as a backup device, competing head to head with tape devices. Iomega is thus targeting small-business owners and workgroups at larger companies who are looking for inexpensive backup solutions that can be stored offsite.

Compared to conventional tape media, REV stacks up well – it’s cheaper, faster and offers random access, making it so much easier to pick out a single file to restore. Compared to DDS tape, REV is about three times faster. The drive itself is cheap, much less than you’d pay for a DDS, AIT or DLT-based entry-level tape streamer. The only fly in the ointment is the absence of any cartridge changers at present, which severely hampers its claims to be a serious alternative to tape. With many PCs shipping these days with 160GB hard disks, manually swapping a handful of 35GB REV cartridges to back it up is less than appealing. However, a jukebox mechanism is in the pipeline for Q3 2004, we are promised. In any event Iomega is looking to double the capacity of REV every 18 months, eventually hitting 0.5TB in five years time.

Iomega REV disks have a 35GB native capacity and, if we’re to believe the label will hold 90GB compressed using the bundled Iomega Automatic Backup Pro software. Anyone who’s ever done any backing up knows to keep a pinch of salt handy when reading these claims, as compressed capacities invariably fail the reality test. Much of the data responsible for the explosion in hard disk capacities is digital media, much of which is already compressed and incapable of being squashed any further.

Interestingly, the REV, despite being what is essentially an external hard disk, doesn’t actually mount as such under Windows XP. If it did, it would not require drivers. But it does – if you plug it in without having first installed the drivers, Windows XP recognises it as a CD-ROM. So if you plug in to another PC, you can ‘look but don’t touch’.

After the drivers are installed, Windows sees it as an optical drive using the UDF file system. When it is installed, it appears as an ordinary drive and so it is compatible with most popular backup and disaster recovery software. REV uses the UDF file format to avoid NTFS limitations on removable media and FAT32 to avoid size limitations. The drive uses the same error correction system - UDF 1.02 - as optical drives, though it’s an older version of UDF. Iomega is using this version because a variety of operating systems contain native UDF 1.02 readers, which increases the number of platforms that the REV can work with. However, it’s not possible to defrag UDF drives.

The Mac version will initially use the HFS+ file system and so Mac RRDs won’t be interchangeable with Windows – we’ll have to wait for a MacOS X UDF file system before we see that. On the Linux front, according to Iomega it’s actively involved with the open source community for the development of a Linux-friendly UDF specification. It’s also possible to boot from a REV, which makes it useful as a disaster recovery tool and to this end a version of Norton Ghost is shipped with the drive. The future SATA and SCSI versions will support ‘Boot and Run’, an option which turns a REV in to your primary system drive, useful if you want to clone your real primary drive. It also ships with Iomega’s Automatic Backup Pro software, a ‘real-time’ backup utility. Its operation is almost invisible – you nominate a folder to backup, say the My Documents folder, which is then backed up in full.

It then monitors that folder for any changes and these changed files are incrementally backed up, automatically. You can even tell it to keep up multiple revisions of documents (up to 99!). Other advanced features of this very useful tool include open-file backup, complete system imaging and restoration, compression and AES encryption.

Backing up the same folder as above, took 21mins 15secs using Windows Backup and produced a 704Mb backup file. Using Automatic Backup Pro, the size of the backup shrank to 523MB, about 75 percent of the original files. This was a creditable size reduction but was well short of the maximum 2.6:1 compression promised. It was also slow, very slow, taking a whopping 66mins to complete the back up.

OUR VERDICT

As straight external storage the REV isn’t a compelling proposition. But as an alternative to tape it offers good ease of use and lower TCO than rival tape solutions. However, getting companies to swap over from familiar tape drives to an external hard disk as their prime backup device may take some doing. The initial REV models, although a tad disappointing in terms of performance, bode well for the future, with SATA and SCSI (and the autoloader) promising to tap its full potential. Iomega’s bold reliability claims will have to stand the test of time but, for the moment, the REV is a capable backup device.