Thanks, it takes much longer time, but the filesize is only 1/5 of the tar size, so it's ok.Try export TMPDIR=/var/tmp.Also, unless you have a really good reason to be using -Ft dump format, I'd recommend -Fc format instead. It's better tested and doesn't suffer from various limitations of the tar format, notably the need for a temp file.
Also great with the TMPDIR hadn't thought about that. Poul