Hi, I do have a Tandberg Exabyte Magnum 224 Tape Changer with an included IBM Ultrium-TD4 drive. Works fine but I haven't found a way to disable the hardware compression.

Any ideas? Perhaps another one of these nst* devices?

backup@chronos:/etc/amanda/a2g$ ls /dev/nst0*
/dev/nst0 /dev/nst0a /dev/nst0l /dev/nst0m
SCSI Robot Changer:

scsiinfo -i /dev/sg5

Inquiry command
---------------
Relative Address 0
Wide bus 32 0
Wide bus 16 1
Synchronous neg. 1
Linked Commands 0
Command Queueing 0
SftRe 0
Device Type 8
Peripheral Qualifier 0
Removable? 1
Device Type Modifier 0
ISO Version 0
ECMA Version 0
ANSI Version 4
AENC 0
TrmIOP 0
Response Data Format 2
Vendor: EXABYTE
Product: MAGNUM 224
Revision level: C304 V1C304 012611
SCSI Tape Drive:

root@chronos:~# scsiinfo -i /dev/nst0

Inquiry command
---------------
Relative Address 0
Wide bus 32 0
Wide bus 16 1
Synchronous neg. 1
Linked Commands 0
Command Queueing 0
SftRe 0
Device Type 1
Peripheral Qualifier 0
Removable? 1
Device Type Modifier 0
ISO Version 0
ECMA Version 0
ANSI Version 3
AENC 0
TrmIOP 0
Response Data Format 2
Vendor: IBM
Product: ULTRIUM-TD4
Revision level: 97F0
tapetype.conf:

define changer tandberg {
tapedev "chg-robot:/dev/sg5"
property "tape-device" "0=tape:/dev/nst0"
property "fast-search" "true"
device-property "BLOCK_SIZE" "64k"
# device-property "COMPRESSION" "no"
}
# ...
tapedev "tandberg"

tapetype U4

define tapetype U4 {
comment "IBM Ultrium TD4 "
length 800gb
}
runtapes 10
labelstr "^a2g-[0-9]+$"
backup@chronos:/etc/amanda/a2g$ amtape a2g inventory
slot 1: label a2g-0 barcode A00058
slot 2: label a2g-1 barcode A00054
slot 3: label a2g-2 barcode MJE992 (current)
slot 4: label a2g-3 barcode A00012
slot 5: label a2g-4 barcode A00017
slot 6: label a2g-5 barcode A00057
slot 7: label a2g-6 barcode A00016 (in drive 0)
slot 8: unknown state
slot 9: unknown state
slot 10: unknown state
slot 11: unknown state (import/export slot)
test with compression:

backup@chronos:/etc/amanda/a2g$ amtapetype a2g -f /dev/nst0
Checking for FSF_AFTER_FILEMARK requirement
Applying heuristic check for compression.
Wrote random (uncompressible) data at 57989690.7540984 bytes/sec
Wrote fixed (compressible) data at 75263215.6595745 bytes/sec
Compression: enabled
Writing one file to fill the volume.
^Cle 1, block 68464 (Strg-C pressed)