I am using a Tandberg Data 1x7 Magnum LTO4 Autoloader. When I use gnutar with a 
block size of 2048 (tar -b 4096) I can back up a 2.6 gig iso file in 37 
seconds. When I use amanda, the same file takes 4 minutes. I used the following 
configure line when I compiled my amanda installation.

/downloads/amandasource/amanda-2.6.0p1/configure --with-maxtapeblocksize=2048 
--with-user=amandabackup --with-group=disk --with-configdir=/etc/amanda

I then added the blocksize line to my amanda.conf

define tapetype LTO4 {
comment "LTO4 Library"
length 802816 mbytes
blocksize 2048 kbytes
filemark 0 kbytes

It still takes 4 minutes.

How do I know if the maxtapeblocksize parameter is active. Is there a log file 
that will tell me what block size the job was backed up with?