My tapedev entry that works is tapedev "/dev/nst0" not  tapedev "tape:/dev/nst0"

I have used the follow tape specific entries in my amanda.conf:

tapedev "/dev/nst0" # Linux @ tuck, important: norewinding

tapetype LTO4 # what kind of tape it is (see tapetypes below)
labelstr "^FULLBACK-[0-9][0-9]*$" # label constraint regex: all tapes must match

#diskdir "/var/tmp/amanda" # where the holding disk is
#disksize 10000 MB # how much space can we use on it
infofile "/var/lib/amanda/fullback/curinfo" # database filename
logfile "/var/log/amanda/fullback/log" # log filename

indexdir "/var/lib/amanda/fullback/index"

define tapetype LTO4 {
comment "LTO4 Library"
        length 802816 mbytes
        filemark 0 kbytes
        speed 93057 kps

}