Ecrix VXA Tape Drive
Just when you think you’ve seen high-capacity tape formats standardize on AIT, DLT, DAT, and Travan formats, along comes another. This one has promise. For one thing, the Ecrix VXA offers 66GB of storage backed up at 6MBbps. For another, the tape drive lists for $899 ($1049 external), a better price-per-gigabyte than any of the other formats. For yet another, the Ecrix VXA has some really neat features that endear it to anyone who needs to back up large quantities of data.
Let’s start with the physical unit itself. Ecrix sent us an external VXA-1 drive. The drive itself is two inches high, six inches wide, and 8 inches deep. It’s larger than a Travan or DAT drive, but smaller than a DLT drive. The front panel has a power LED, a socket for the tapes, and four stats lights. The back panel has dual SCSI-2 connectors and can run in single-ended, fast and narrow, or Ultra LVD formats of SCSI-2. A power switch and a DB-9 serial connector complete the back panel. The case of the unit is attractive in an industrial-design way, with rubber accents acting as legs on all eight top and bottom corners.
The tapes used by the Ecrix VXA are similar to DAT or AIT cartridges in size, but are not compatible with any other tape units. The Ecrix VXA tape system is what makes the drive special. It’s divided into three areas: Discrete Packet Format (DPF) to control the way data is written in packets to the tape; Variable Speed Operation (VSO) which adjusts tape speed to match data write or read requirements; and OverScan Operation (OSO) which allows data to be read without regard to track geometry or layout and allowing overscanning of damaged tape areas. While the alphabet soup may sound like marketing blurb, in fact the technologies have sound engineering principles and work very well.
We tested the Ecrix VXA on several systems, including SCO OpenServer, SCO UnixWare, Corel Linux, and Windows NT. Configuring the drive as a standard SCSI device eliminates the need for special drivers under SCO operating systems while a supplied CD-ROM provides drivers for some OSs. We tested with standard UNIX backup utilities (tar and cpio) as well as with Lone-Star’s Lone-Tar and EST’s BRU. On the Windows platform we tested with ArcserveIT. To start, we conducted backups of the servers themselves but quickly moved to network-wide backups.
The first thing we note is that 66GB is not a compressed best-case capacity. We got 60 to 66GBGB consistently regardless of the type of data we were backing up. The Ecrix VXA does use a 2:1 compression algorithm meaning a native capacity of 33GB, but with compression active we almost always got close to the 66GB mark. The second thing of note is the speed of the backup. We backed up 60GB of data in just over three hours, about the same time it takes our AIT drive to back up 25GB. Seek times for recovery of files was fast, averaging less than a minute for a file at the beginning of the backup and five minutes for a file at the end of the tape. The drive is quiet in operation.
We compared the Ecrix VXA with a Sony AIT drive, a Quantum DLT drive, an HP Travan T20 drive, and an HP DAT 24e drive. The media costs for the Ecrix are lower than the AIT, DLT and T20 cartridges, although they are available only from limited sources (including Ecrix, of course). The tape drive itself is much cheaper than a DLT or AIT drive, the only real competition in capacity. The 24GB DAT and 20GB T20 can be found more inexpensively, but you need three cartridges to rival the Ecrix VXA’s capacity. You won’t find VXA tapes in your local superstore (yet). For speed of backup per gigabyte, the Ecrix VXA was on a par with the DLT and AIT drives, but faster than both the Travan and DAT drives. For data restorations, the VXA was faster than all but the AIT (which has an embedded memory ship holding the tape’s content files).
A definite plus for the Ecrix VXA comes in restoring data from a tape with a bad sector. Most drives, such as DLT and DAT, will cancel the restoration when a bad tape block is encountered. Not the Ecrix VXA; it keeps on restoring after the bad block. Ecrix is justifiably proud of this feature, as well as the tape drive’s robustness. Their web site contains stories of freezing and boiling VXA tapes, then using them at room temperature without a flaw. We wanted to try this type of extreme test too, but settled for an accidental test instead: the review’s dog managed to grab a tape cartridge off the desk, chew on it for a while, and add large quantities of saliva to the tape itself. After a dunking in filtered water, the cartridge was left to dry. A day later, all the data on the tape was read perfectly. Dog-proofing your tape backups may not be high on your list of emergency procedures, but it shows the robustness of the tape. We wouldn’t expect that kind of recovery from DLT or DAT tapes.
Whether the Ecrix VXA format catches on or not is ultimately up to the market. However, the tape drive is much less expensive than DLT and AIT drives. The per-gigabyte of storage price is a third that of DAT, and a quarter that of AIT and DLT. The drive performs perfectly with every OS we tested, and the drive is fast and quiet. Instead of laying out thousands of dollars on a DLT drive, take a very careful look at the Ecrix VXA: you just may have found a new high-capacity tape format you can live with. And get a dog in your server room with the money you save.
5525 Central Avenue
Summary: The most cost effective high-capacity tape drive on the market, rugged, and supportive of most operating systems. Proprietary tapes are the only (minor) down-side.