Joe Konecny wrote:

Am I correct in thinking that if I am backing
up only the server running amanda then it makes
no sense to use the holding disk?

It still does make sense.  The use of the holdingdisk makes greater
guarantee that the tapedrive keeps streaming, especially in combination
with gzip software compression.
Tapedrives with 3, 6 or even 15 Mbyte/sec throughput are not an
exception anymore. Unless you have very very fast hardware, the
normal backup programs cannot keep up with that speed.

And there are the cases when there are problems with the tapedrive
(wrong tape, holiday period, operator couldn't make it in the office
because he's sick etc.)
Having (at least incremental) backups on holdingdisk is a nice
fallback.

The backside is that the total backup procedure can be longer in some
cases.  The writing to tape only starts when a backup image is complete
on disk.  But the actual dump phase is usually faster, also a nice feature.

--
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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