[ Thanks to Robert
McMillan for this link. ]
“The best protection against hardware failures and user errors
is to back your system up on a regular basis. Ecrix’s attempt to
make backup chores less taxing is the VXA-1 tape drive, which
stores up to 66 GB of compressed data per tape cartridge.”
“Another key issue Ecrix is addressing with the VXA-1 is the
reliability of backups. We’ve all heard stories of the sysadmin
who, under pressure, discovers that a tape drive can’t read a
backup it created and verified just days ago. Unlike other tape
drives, the VXA-1 mimics the way TCP/IP data is sent across the
Internet. TCP/IP breaks your data into packets and then reassembles
it at the destination, even if the packets have arrived in a
different order from that in which they were sent. Similarly,
the VXA-1 stores your data on tape in 64-byte pieces, each
tagged with error-correction information and an identifier that
indicates its place in the data stream. This allows the drive’s
four heads to try to read each data packet independently —
possibly reading them out of order when the tape is misaligned,
damaged, or stretched — and still rearrange them as needed.”
“The external VXA-1 we tested worked extremely well. We attached
it to an Adaptec 2940AU PCI card and accessed it from Linux as
/dev/st0. We performed backups of an entire Linux installation
using Merlin Software Technologies’ PerfectBackup, and also wrote a
single file of several hundred megabytes to the drive with the tar
command. We also tested the drive briefly with the BRU and Arkeia
backup programs.”