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time for LDM to transfer a 200Mb file (fwd)


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Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
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---------- Forwarded message ----------
Date: Wed, 06 Sep 2000 17:23:10 -0600
From: Russ Rew <address@hidden>
To: address@hidden
     address@hidden
Subject: time for LDM to transfer a 200Mb file

Mike,

I reported earlier the difference between using "cp" (from a local to
an NFS-mounted file system) versus using "ftp" to transfer a single
200 Mbyte file from buddy to zero:

  cp  122 sec
  ftp  41 sec

Just for completeness, I timed the LDM doing the same thing:

  ldm  64 sec

These are "real time" as reported by the "time" command.  This is
actually the time transferring the bytes of a 200 Mbyte "product" from
an LDM product queue on buddy to an LDM product queue on wcfields.  It
does not count the time it took on buddy to compute the MD5 signature
and insert the file into the product queue (about 39 sec) nor the time
it takes to pqcat it out of the product queue into a file on the other
host (about 29 sec).  Just copying it on a local disk on zero using
"cp" took about 66 sec, so is actually slower than ftp to a remote
host!  I only tried these once on zero, so you should probably take
them with a grain of salt ...

--Russ