I followed this howto here
http://www.howtoforge.com/disk_based_backups_amanda_debian_etch
and of course adjusted for my os but when I run a backup I get an email
containing

These dumps were to tape DailySet1-2.
The next tape Amanda expects to use is: DailySet1-3.

FAILURE AND STRANGE DUMP SUMMARY:
  bigfish.bluelight.org.uk  /  lev 0  FAILED [disk /, all estimate failed]

bigfish# more amanda.conf
mailto "root"
tapecycle 6 tapes
tapetype DISK
tpchanger "chg-disk"
changerfile "/usr/local/etc/amanda/DailySet1/changer"
tapedev "file:/mnt/usr_f/dumps/amandatapes/DailySet1"


define tapetype DISK {
   comment "Backup to HD"
   length 3072 mbytes
}

define dumptype root-tar  {

   comment "tar dumptype"
   compress client fast
   program "GNUTAR"
   strategy standard
   priority high

bigfish# more disklist
bigfish.bluelight.org.uk / root-tar

bigfish# more tapelist
20080413 DailySet1-2 reuse
20080412 DailySet1-1 reuse
20080412 DailySet1-6 reuse
20080412 DailySet1-5 reuse
20080412 DailySet1-4 reuse
20080412 DailySet1-3 reuse

any pointers welcomes
Thanks