Kim,

My own testing shows that the problem is the multiplexing.  Multiplexing is
best used for slow networks or backups that include a lot of little files.
When you multiplex across a fast network (we're using GigE as well), the
drives end up slowing down or stopping as the streams alternate to tape.
When we disabled multiplexing for testing purposes (don't have the hardware
resources to do it permanently yet), we went from roughly 4.5mb/sec to 8.5 -
9mb/sec.

Ken Zufall
Technical Analyst
Phone: 216.471.3613
Pager: 440.303.1656
Fax: 216.491.4051

"It's not the most intellectual job, but I do have to know all the letters."
Vanna White



                -----Original Message-----
                From:   Pearson, Kim (STP) [mailto:kim.pearson AT guidant DOT 
com]
                Sent:   Tuesday, February 13, 2001 5:16 PM
                To:     'Veritas-bu AT mailman.eng.auburn DOT edu'
                Subject:        [Veritas-bu] Sun Gigabit Performance

                What is the best way to benchmark network throughput? We are
using 2 Gigabit
                ethernet ports on our NetBackup Master/Media server, and we
are not seeing
                the throughput we are expecting for backups. Since we stream
multiple
                classes to each drive, I'm inclined to believe that it's the
network, not
                the 8 DLT drives.  They sit idle a lot...shoe shining? We
are using crude
                copy scripts now to try to measure throughput - anyone got
something better?

                HW - Sun E450, 2 Sun Gb PCI cards dedicated to the backup
segment...

                Thanks!

                Kim
                Kim Pearson
                UNIX Team Lead
                Guidant Corporation
                kim.pearson AT guidant DOT com

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