Amanda weekly tape rotation

Question

I'm having an issue creating a consistant weekly rotation which includes a full with incrementals. The idea is to have a rotation of one disk on site and one disk off site with each having a full backup with incrementals that are independent of the other disk. The backups work, but when doing restore tests, multiple drives are required.

The full dataset to backup is about 750GB with about 1Gb growth a week. I have (2) 1TB USB hard drives being swapped and mounting to the same mount point, and my amanda config looks like:

org "MyConfig"
infofile "/etc/amanda/MyConfig/state/curinfo"
logdir "/etc/amanda/MyConfig/state/log"
indexdir "/etc/amanda/MyConfig/state/index"

#tpchanger "chg-disk:/amanda/vtapes"
#labelstr "MyData[0-9][0-9]"
#autolabel "MyData%%" EMPTY VOLUME_ERROR
tapecycle 3
dumpcycle 7 days
#amrecover_changer "changer"

 autolabel "$m-%%%" any
 meta-autolabel "$c-%%%"
 define changer removable-disk {
    tpchanger "chg-disk:/amanda/vtapes/"
    property "NUM-SLOT" "7"
    property "AUTO-CREATE-SLOT" "yes"
    property "REMOVABLE" "no"
    property "MOUNT" "no"
    property "UMOUNT" "no"
    property "UMOUNT-LOCKFILE" "/etc/amanda/MyConfig/disk.lock"
    property "UMOUNT-DELAY" "1"
 }
 tpchanger "removable-disk"

tapetype "HDBACKUP"
define tapetype HDBACKUP {
  length 500 gbytes
  filemark 500 kbytes
}

define dumptype simple-gnutar-local {
    auth "local"
    compress client fast
    program "GNUTAR"
}
define dumptype global {
    comment "Global definitions"
    auth "bsdtcp"
}

define dumptype root-tar {
    global
    program "GNUTAR"
    comment "root partitions dumped with tar"
    compress none
    index
    priority low
}

define dumptype user-tar {
    root-tar
    comment "user partitions dumped with tar"
    priority medium
}
define dumptype comp-user-tar {
    user-tar 
    compress client fast
}

holdingdisk hd1 {
    directory "/var/amanda/holding"
    use 50 mbytes
    chunksize 1 mbyte
}

Thank you for your time and help!