As Frank already noted, you are taping direct to tape,
not using your defined holding disk.

>
> holdingdisk hd1 {
>    comment "main holding disk"
>    directory "/tmp/amandahld"   # where the holding disk is
>    use 20000 Mb        # how much space can we use on it
>    chunksize 1Gb       # size of chunk if you want big dump to be
> }
>

Is your /tmp directory (file system) large enough to support a
20GB holding disk and all the other uses you might have for it?

> # dumptypes
>
> define dumptype global {
>    comment "Global definitions"
>    tape_splitsize 20000 mbytes
>    split_diskbuffer "/tmp/amandasplit/split"
>    index yes
>    holdingdisk yes
> }

You really do like /tmp don't you?

If I understand tape spanning correctly, and
if we are going direct to tape, which we are, you will need
at least 2 x 20GB for the split buffers.  One being filled
and another dumping to tape.

Now do you have over 40GB on your /tmp plus if any other
DLEs are dumping in parallel to the holding disk (also on
/tmp) maybe as much as another 20GB.

OK, will try tweaking the holding space for the backup this weekend.

STATISTICS:
                         Total       Full      Incr.
                       --------   --------   --------
Estimate Time (hrs:min)    0:13
Run Time (hrs:min)        74:25
Dump Time (hrs:min)       74:11      74:11       0:00
Output Size (meg)      862907.9   862675.3      232.6
Original Size (meg)    860212.0   859979.4      232.6
Avg Compressed Size (%)     --         --         --    (level:#disks ...)
Filesystems Dumped            4          2          2   (1:2)
Avg Dump Rate (k/s)      3308.7     3307.9    21274.4

Tape Time (hrs:min)       74:07      74:06       0:00
Tape Size (meg)        862908.0   862675.3      232.7
Tape Used (%)             456.7      456.6        0.1   (level:#disks ...)
Filesystems Taped             4          2          2   (1:2)
  (level:#chunks ...)
Chunks Taped               86270       86268          2   (1:2)
Avg Tp Write Rate (k/s)  3312.0     3311.3    25150.8

USAGE BY TAPE:
 Label        Time      Size      %    Nb    Nc
 000213      23:49 282131616K  145.9     3  27617
 000214      23:27 282261408K  145.9     0  27651
 000221      20:26 230629344K  119.2     0  22593
 000227       6:23 85834944K   44.4     1  8409


FAILED AND STRANGE DUMP DETAILS:

/--  files.int /raid01/PUBLIC lev 0 STRANGE
sendbackup: start [files.int:/raid01/PUBLIC level 0]
sendbackup: info BACKUP=/bin/gtar
sendbackup: info RECOVER_CMD=/bin/gtar -f... -
sendbackup: info end
? gtar: ./temp/Track 03.mpg: Warning: Cannot stat: No such file or directory
? gtar: ./temp/Newdoc.txt: Warning: Cannot stat: No such file or directory
| Total bytes written: 777687869440 (725GiB, 3.2MiB/s)
sendbackup: size 759460810
sendbackup: end
\--------


NOTES:
 planner: Adding new disk www.int:/raid01.

 taper: tape 000213 kb 283015264 fm 27618 writing file: Input/output error

 taper: tape 000214 kb 283146272 fm 27652 writing file: Input/output error

 taper: tape 000221 kb 231352352 fm 22594 writing file: Input/output error

 taper: tape 000227 kb 86104032 fm 8409 [OK]