I have a IBM LTO-3 ULT3580-TD3. When I try write something to tape always it returns only zeros but with good length (/size).
# dd if=/media/test1 of=/dev/nst0 bs=64k
# dd if=/dev/nst0 of=/media/test2 bs=64k
# ls -l /media/test*
-rw-r--r-- 1 root root 1073741824 05-11 21:54 /media/test1
-rw-r--r-- 1 root root 1073741824 05-11 21:56 /media/test2
# od -x /media/test2
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
10000000000
# od -x /media/test1 | head
0000000 c4e3 f1b6 e95b 944c 7439 789d 0424 744c
0000020 16a2 f530 57ff cb33 71c2 8326 d888 aa79
0000040 fdbc 1cb9 279d b97c 66a5 eabb 3a70 adc1
0000060 02a6 a96c 31c6 59b1 6ee6 c8dc da2b 21f1
0000100 6bc4 3d5e 17b4 260d 7285 2a52 a0b7 3ee6
0000120 f206 588c 0758 5ad5 f4a4 ca2f 7f9b 1dad
0000140 7adb 8eba 7593 9ff8 7997 fd90 4ae1 7d47
0000160 f2ac bb13 6fe8 0a49 ef7a 77b0 5394 7058
0000200 1f8e d95b 03d6 6a0d 7680 9f42 9eb7 2931
0000220 8752 ae30 6d19 2096 94ef 7d76 0aa6 5cd9
I saw that speed of dd is about 100MB/s, this is LTO-3 so it should be about 80MB/s and not always drive working, most time of writing is idle.
Tapedrive is connected via FibreChannel
08:00.0 Fibre Channel: Emulex Corporation Zephyr LightPulse Fibre Channel Host Adapter (rev 02)
bootup log:
[ 6.268892] lpfc 0000:08:00.0: 0:1303 Link Up Event x1 received Data: x1 x1 x10 x2 x0 x0 0
[ 6.268893] lpfc 0000:08:00.0: 0:1309 Link Up Event npiv not supported in loop topology
[ 6.276073] scsi 6:0:0:0: Sequential-Access IBM ULT3580-TD3 88M0 PQ: 0 ANSI: 3
[ 6.276191] scsi 6:0:0:0: Attached scsi generic sg6 type 1
