Hi,
I have a question about how the planner schedules dumps and its
interaction with the tapetype definition.

In my home config, I use a Seagate Scorpion 24 with DDS2 tapes and the
following definition:

define tapetype Python-DDS2 {
    comment "ARCHIVE Python with DDS2 tape"
    length 3860 mbytes
    filemark 16 kbytes
    speed 707 kps
}

3860 MB/1024 = 3952640 KB

I think this is sensible, knowing that DDS2 is 4GB native (4194304 KB). 
I use software compression, so AMANDA should have an accurate idea of
how much data she wants to write.  From the tapetype above, she should
know how much tape she has to play with, and I should hope that even if
she writes all 3860 MB, that still leaves a little cushion at the end of
the tape.

Trouble is, I've seen AMANDA try to write more than this to a tape, and
hit an EOT.  She tried to write more data than the tapetype told her she
could.  That's what I don't understand.

For example:

STATISTICS:
                          Total       Full      Daily
                        --------   --------   --------
Estimate Time (hrs:min)    0:09
Run Time (hrs:min)         1:50
Dump Time (hrs:min)        1:31       1:29       0:01
Output Size (meg)        3846.6     3844.9        1.7
Original Size (meg)      4023.8     4002.5       21.3
Avg Compressed Size (%)    60.2       62.8        7.8   (level:#disks
...)
Filesystems Dumped           15         11          4   (1:4)
Avg Dump Rate (k/s)       722.2      734.0       18.9

Tape Time (hrs:min)        0:59       0:59       0:00
Tape Size (meg)          2450.8     2449.0        1.8
Tape Used (%)              63.5       63.5        0.0   (level:#disks
...)
Filesystems Taped            14         10          4   (1:4)
Avg Tp Write Rate (k/s)   705.5      705.7      546.3

and in NOTES:

taper: tape small07 kb 3896224 fm 15 writing file: No space left on
device

So it tells me that when AMANDA hit that EOT, she was already beyond the
limit defined in the tapetype.  Why was she doing that?  I'm interested
to know if I need to tweak the tapetype a little more.

On a related note: Does anyone know whether native tape capacities are
advertised the way hard drives are (where 1GB = 1000 MB instead of 1024
MB).  Although even if this were the case, I'd still expect to get
4096000 KB on the tape, and AMANDA hit EOT at 3896224 KB, almost 200 KB
shy.  How much variance is there in actual usable capacity vs.
advertised native capacity?

Thanks,
Eric