Timothy
Parker Consulting Incorporated
|
|
|
|
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. Ecrix VXA 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. |
|
Send mail to
tparker@tpci.com with
questions or comments about this web site.
|