At 11:41 AM 3/9/99 -0700, Kelly J. Lipp wrote:
>Yup, I agree.  However, I think most sites will see lower overall
>performance, that is backups will take longer, with compression at the
>client than without it.
>
>Kelly J. Lipp

Kelly,

Not being sure about the basis of your thinking, I'll go ahead and venture
some more thoughts of my own.  I'll be up front about this, however - I
have not done any kind of performance studies on this.  These opinions are
based simply on gut instinct and how I think things work.

As long as you do not have a bottleneck getting data into your server,
either on the network, network adapter, ADSM server disk, database I/O,
etc, then I think you may be correct - backup performance could very well
be better without client compression.  However, my thinking is that
eventually you will end up with a bottleneck on one or more of these
resources, and you are more likely to end up with it sooner if you do not
use client compression.  At that point, overall performance (IMHO) will be
worse.

One other thought:  We chargeback based on ADSM storage usage.  Client
compression provides a fairer algorithm for this calculation than tape
hardware compression.  With the former, a Q OCC will show the true storage
utilization, whereas the latter will not.  This is not the reason that we
do client compression, but it is something to consider.

Regards,
..Paul