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Verifying files after transfer? (checksum, md5)

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The Question is:

 
Hallo Mr Wizard,
 
I am looking for information on the VMS checksum command, compared to the
unix command. The background to my question is that I have the pleasant task
of replacing a sun solaris box which is not y2k ready with a VMS system
which will function as a gateway
. Files will be sent via ftp to me from three other solaris boxes. We want
to double check that the files hare arrived complete, as incomplete files
might crash the applications and cause a currupt database.
 
One idea we had was to do a checksum on the files on the unix boxes and then
a checksum at the VMS end. However we have found that the results of these
commands do not seem to be comparable, the results are quite different. We
were wondering if there is a
n explanation for the difference between these commands, or if we just knew
how to interpret the results, we might be able to use checksum as a test.
The alternative we are considering is to ftp-put a file from unix to VMS,
then ftp-get it back again and
checksum the returned file against the original. This is rather time and
space consuming and we would like to do something more elegant.
 
Do you have any ideas?
 
Regards and best wishes to you all,
 
Kevin Mannerings
Perot Systems Corporation
Zuerich
Tel 0041 1 23 96370

The Answer is :

 
  The (undocumented) OpenVMS CHECKSUM command is a simple CRC operation.
  It is not intended to be compatible with any other particular CHECKSUM
  command from any other platform.
 
  Probably the easiest approach would be to copy the files twice, and
  DIFFERENCE the results.
 
  Also consider using a tool such as MD5 for this:
 
    http://www1.service.digital.com/svctools/decevent/md5-frame.html
 
  or alternatively, one of the available ZIP tools.

  
     
     answer written or last revised on ( 11-OCT-1999 )
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