Jon LaBadie wrote:

On Wed, Aug 17, 2005 at 09:13:22AM -0400, Mangala Gunadasa wrote:

[...]

backup takes 9hrs to finish. We have tried to make it more efficient by
changing the parameters "interface", and "net usage" of the amanda.conf
and did not succeed( Probably those parameters do not matter). We would
like to perform Full backup every Day to a SDLT Tape drive.
 [...]

Seconding Dave's comments, figure out what pieces of the backup take time.

Thirding!  Oh well, you know what I mean.

One additional thought, see if the estimate phase is an appreciable
part of the total time.  As you are doing full backups daily, I presume
you have a pretty good idea of the amount of data daily.  In that case
newer versions of amanda have alternatives to the estimate phase that
can greatly speed up that part of the backup.

Indeed, especially when using gnutar the estimates can take
a lot of time.
I use these parameters in my archive backups that do
full backups only.  I do not want any incrementals at all, even
if the tape is full, and do not want to waste time on estimates
for incrementals either:

    define dumptype global {
        program "GNUTAR"
        index yes
        record no
        compress client fast
        skip-incr yes           # emphasize we only want full dumps
        strategy noinc          # also reduce time to do estimates
   }


If you have have really really fast servers, then adding "maxdumps 2"
or even more, together with a careful indication of splindlenumbers in
the disklist allows amanda to start more than one dump on one host
at a time.

Other general tips:  make sure you have enough holdingdisk space.
Then the backups themselves can finish as fast as they can, without
tapedrive speed constraints.

Also the command "amplot" can greatly help pointing to bottlenecks.


--
Paul Bijnens, Xplanation                            Tel  +32 16 397.511
Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM    Fax  +32 16 397.512
http://www.xplanation.com/          email:  Paul.Bijnens AT xplanation DOT com
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