I'm working on setting up a automated backup system using amanda
2.4.4p4 on a linux slack 8.1 server. The tape system is a HP DAT 72x6
autoloader (36/72 GB tapes)

Q1: Using tapetype I got the following entry:

define tapetype HP-DAT-72x6 {
    comment "HP autoloader DAT 72x6"
    # data provided by Rodrigo Ventura <yoda AT isr.ist.utl DOT pt>
    length 31255 mbytes
    filemark 527 kbytes
    speed 1580 kps
}

How can I setup amanda to be less conservative, i.e. assume it can
record a little bit more than 31GB per tape? Is there a parameter
where I can specify the assumed compression ratio, say, something
between 1:1 and 1:2?

Q2: I'm getting "strange" messanges in dump, mostly related with
sockets ignored by gnutar, temporary files (mail queue) being
manipulated, etc. It seems this is the cause of several dumps being
promoted N days ahead... Is there a way to make amanda ignore such
messages? I can live with backups without those files. But I can't
live with amanda promoting dumps several days ahead, all the time
(they never get dumped this way!).

In other words, what exactly makes amanda promote a dump N days ahead?
How can I know whether the promotion message is safe to ignore or not?

Q3: I setup amanda in my server, and currently I'm running it
everyday. However, I want to increase the dump cycle, letting amanda
run, say, three times a week. Is it safe to change such parameters as
dumpcycle and runspercycle in mid-cycle? Say, if I change them right
now, will it keep on working without further operations?

Q4: Following the previous question, is it safe to incrementaly add
entries to disklist?

Thank you,

Cheers,

Rodrigo Ventura