On Fri, 6 Sep 1996, Sheelagh Treweek wrote:

> On Friday, 6 Sep 1996 Andreas Floeter <Andreas.Floeter AT AIRBUS DOT DE> 
> wrote:
>
> >Your throughput is (8*1024)/(40*60) = 3.413 MB/sec. That is 1/3 of the
> >theoretical performance of the drives. To which degree is your database
> >filled? Have you seen faster values? We are considering buying 3590, so I
> >am curious about all informations I can get.

Currently, we use an Exabyte EXB-480 with 4 EXB-8505XL. We get 1.5GB
database backed up in 17min, 1.5*1024/(17*60)=1.505. This figure can only
be explained since the database is filled by 50%.

> The very best performance we get is about 5 MB/sec on BACKUP STG with a
> large average filesize (greater than 1 MB). The very worst is about
> 1 MB/sec on MIGRATION with a very low average filesize (less than 80KB).
> Our (full) DB backup  takes about an hour currently - about 11-12 GB.

We also see that backup performance is degrading with many small files.
Also the performance is better for selective backups instead of
incremental, since mostly communication between the client and server is
done.

[...]


______________________________________________________________________
Disclaimer: These are my views and not those of my employer.

                        Andreas Floeter
Phone: +49 40 74 37 - 48 50     FAX: +49 40 74 37 - 27 55 (or 47 60)
email: Andreas.Floeter AT airbus DOT de

                Daimler-Benz Aerospace Airbus GmbH
Kreetslag 10, 21129 Hamburg; Postfach 95 01 09, 21111 Hamburg, Germany