Question about Verification

[laarree]

When Retrospect 5 verifies a backup, is it actually doing a bit-by-bit

 

compare of the source files to the destination files, and therefore

 

a successful comparison implies that a backup is a perfect copy?

 

 

 

I'm asking because I just did a successful multi-gigabyte backup

 

to my VXA-1 Ecrix SCSI LVD tape drive in MacOSX 10.1.5 which

 

is hooked up to an Adaptec 2940U2B SCSI LVD card in my

 

B+W G3 (first time tried in MacOS X). According to Dantz's page

 

on MacOS X SCSI host adapter compatibility:

 

 

 

"The problem, which affects all versions of Mac OS X including

 

10.2 (Jaguar), is not application specific. Rather, incorrect data

 

is passed by the SCSI card to and from any program communicating

 

with a SCSI device. The result may simply be an inaccessible device,

 

or worse, data corruption can occur."

 

 

 

and according to Dantz forum veteran AmyC on 4/19/02:

 

 

 

"The Adaptec 2940U2B is fully unsupported by Retrospect on OS X.

 

This adapter was heavily tested and failed in every case. When

 

Retrospect attempts to send data to a tape drive attached to the

 

2940U2B card, a kernel panic occurs immediately. "

 

 

 

Since my backup verified successfully, does that mean that I can

 

trust that the data is correct and uncorrupted, or am I being lulled

 

into a false sense of security by my wily yet evil SCSI card?

 

 

[AmyJ]

The only answer I can provide is: Proceed at your own risk.

 

 

 

You may find yourself in a restore situation and not have restorable data. Most likely, in your case, the data was copied properly, as it verified without error. However, do you really want to take that chance with your data?