Backup is too slow - configuration?

[hochenaw]

Hi,

we have an HP Surestore dlt vs80e and use hp dlt IV tapes (capacity
40/80GB) under linux.
But the backup is to slow, we should have a backup rate of 10.8 GB
(native)/20.6 (comprimized), but we do not have :-(
So i have some questions, to which i did not find answers until now!

In the file tapelist we have following entry (i dont know why):
-
define tapetype HP-DLT {
 comment HP SureStore DLT
 length 80 gbytes   # conservative estimate
 filemark 1 byte# should work given above
 speed 30 mbytes# even more, but this isn't used in
amanda
}
-
length in comprimized (80) or uncommprimized (40) modus?
What does filemark mean?
speed in mbytes per minutes or ...? Does it have any consequence if i
insert to much/less speed?

How can i activate software or hardware compression (cant find an
entry in amanda.conf, just Client or Servers best in dumptypes-file)?

I have differnt directories to backup, and i want to pack them in
_one_  big package, so i specify a chunk size of 20GB, but Amanda
creates for each entry in the disklist one package/file.

A hardware question: If i have many packages to flush out to tape, are
they written at once so that the tape comes into the streaming mode or
does the tape have to be stopped and restartet for each package newly?

What happens if i delete some files in the holding disk manually?
Does it have consequences and the database is corrupted?

What does ignoring cruft file as log message?

I would be happy if someone can help me!
Maybe someone has the same configuration!
Thx a lot, Dalton

When amanda begins to flush?

[hochenaw]

Hi,

thank you for your first answer.

One question again:
Amanda creates the files in the holding disk, when does Amanda begin to write it 
out to tape?

When the first file is created or when all files are created?
In the first case, there can be a short time period where the tape has to be 
stopped to wait for the next package until it is created.

Best regards,
Dalton