Mario wrote:

> Garbage collection true,

This is probably the reason it is so slow. It does a cleanup work in
existing database. Try running without it and see what happens.

> I replicated this on several other small databases backed up the same
> way. Most of the backup time was spent "writing domain RDB$xxx".

That's only because domains are most numerous type of database object.
But I don't believe it was most of backup "time", but perhaps most of
backup "messages".

> I then run restore of the backed database, also form IBConsole (it
> only took a couple of seconds to complete) and backed the restored
> database again. This time the backup took only a few seconds.

Domains were also present here, so they're obviously not the problem.

--
Milan Babuskov
http://www.flamerobin.org