"Rob Turk" wrote in message ...
"Arthur Begun" wrote in message
m...
"Rob Turk" wrote in message
l.nl...
"Arthur Begun" wrote in message
om...
If you are considering a VXA tape drive from exabyte (formerly ecrix)
you should be aware of a fatal flaw. Even though ads show a tape
soaking in a cup of coffee and a claim that the data is still
recoverable, the tape header is extremely fragile. If you are doing a
backup and the computer freezes and requires a hardboot as the header
is written, there is a great chance that the scsi controller version
will wipe out the header and all of the gigs of previous backups on
the tape might as well be gone. It costs thousands to retrieve the
data, and Exabyte will do nothing but give you a list of companies
that recover lost files. After it happened to me I did a google
search and found a post from someone else who suffered the same plight
from 2001 so they have known about the problem since then.

Ehhh?!? Don't know where you get your information from, this is absolute
rubbish.

If you do a backup and your computer freezes halfway into the backup,
the
session in progress will most likely not be valid. This is the case with
any
backup, regardless if it's tape or CD/DVD, and regardless of the type of
tape drive you use. Backup software usually write their index to tape
after
completion of the backup session. If this fails, that specific session
will
most likely be invalid. Any previous sessions will be perfectly
readable.

Rob (who works for Exabyte)


Here is the 2001 post from someone else who lost his VXA header:

http://www.mail-archive.com/retro-ta.../msg02723.html

In my case a hard reboot was enuf to ruin the header and effectively
the 27 gigs of backup on the tape.

What you describe has nothing to do with 'scsi controller wiping out' a
header. It's a condition where the tape drive is powered down during write,
resulting in an inconsistent tape format. Powering down in the middle of a
write session is not a good idea for any data recording device. CompactFlash
can be destroyed by this, CD-RW and DVD-RW is ruined by it, tape drives end
up with incomplete or inconsistent data formats and harddisks may develop
bad sectors from it. This isn't a VXA flaw, it's a "don't do this" common
sense issue.

For your information, should this happen again, the drive is equipped to
detect this condition and has built-in recovery for it. It may take a while,
as the drive needs to read the tape from the begin up to where the write was
terminated by a power loss.

Please note that this recovery re-validates the tape on a block level. It
doesn't mean Retrospect will be able to read from the tape, as it may not be
able to deal with half-a-backup. That's not a device flaw, that's a software
design choise. Retrospect (or any other backup software I know of) isn't
designed to deal with this. Data recovery companies can help you out if they
know the Retrospect format. Your other option is to erase the tape and
re-run your backup.

I find it interesting to see that you post your comment to several
newsgroups on an issue that happened in 2001. Do you also write messages to
car interest groups warning them about Ford because you heard about someone
owning a Pinto?? Do you happen to work for a competitor of Exabyte?

Rob


In case it is not clear to you, the incident happened this past Friday
(1/23/04), not in 2001. When it happened on Friday I talked with
Marty at Exabyte and sent in a log. On Monday I got a call and was
told if the header is gone, tough luck. I was actually using 4.21 of
Backup Exec (not Retrospect) but when the tape that was previously
full of differential backups suddenly turned empty after a backup
froze while writing the header I called Exabyte and also searched
using Google to see if I could find anything else about retrieving the
lost data. I found the 2001 post of someone having a similar problem
using a VXA drive and Retrospect. On the one hand you guys claim that
your drives are more reliable than other formats but as it turns out a
simple software freeze while writing the header blows the header away
and effectively erases the contents of a backup tape unless it is
restored by a data recovery company at the cost of thousands of
dollars.

So to make it absolutely clear, the incident happened afew days ago.
I have a tape on my desk full of data that is inaccessible because
somehow the header was destroyed because software froze while
appending a backup. I consider it a major flaw. I've been doing
backups on tape for almost 2 decades and have never seen a header
destroyed by an appended backup.