Write a 1k block of data to the tape device. # dd if=/etc/passwd of=/dev/st0 bs=1k count=1 1+0 records in 1+0 records out 1024 bytes (1.0 kB) copied, 0.0290604 s, 35.2 kB/s Read the 1k block of data # dd if=/dev/st0 of=/tmp/b1 bs=1k count=1 1+0 records in 1+0 records out 1024 bytes (1.0 kB) copied, 0.00822856 s, 124 kB/s Verify it contains data.. # strings /tmp/b1 at:x:25:25:Batch jobs daemon:/var/spool/atjobs:/bin/bash bin:x:1:1:bin:/bin:/bin/bash daemon:x:2:2:Daemon:/sbin:/bin/bash ftp:x:40:49:FTP account:/srv/ftp:/bin/bash games:x:12:100:Games account:/var/games:/bin/bash gdm:x:106:111:Gnome Display Manager daemon:/var/lib/gdm:/bin/false haldaemon:x:101:102:User for haldaemon:/var/run/hald:/bin/false lp:x:4:7:Printing daemon:/var/spool/lpd:/bin/bash mail:x:8:12:Mailer daemon:/var/spool/clientmqueue:/bin/false man:x:13:62:Manual pages viewer:/var/cache/man:/bin/bash messagebus:x:100:101:User for D-Bus:/var/run/dbus:/bin/false news:x:9:13:News system:/etc/news:/bin/bash nobody:x:65534:65533:nobody:/var/lib/nobody:/bin/bash ntp:x:74:105:NTP daemon:/var/lib/ntp:/bin/false polkituser:x:103:106:PolicyKit:/var/run/PolicyKit:/bin/false postfix:x:51:51:Postfix Daemon:/var/spool/postfix:/bin/false pulse:x:104:107:PulseAudio daemon:/var/lib/pulseaudio:/sbin/nologin root:x:0:0:root:/root:/bin/bash sshd:x:71:65:SSH daemon:/var/lib/sshd:/bin/false suse-ncc:x:105:110:Novell Custom Read the same block of data but specify a larger block size # dd if=/dev/st0 of=/tmp/b1 bs=10k count=1 0+1 records in 0+1 records out 1024 bytes (1.0 kB) copied, 0.00821022 s, 125 kB/s (This returns the correct block size of 1k - good) Now confirm the data is valid. ~ # strings /tmp/b1 ~ # Oops. All the data is NULL And again using hexdump # hexdump -C /tmp/b1 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000400 I'm going to have a look and see if I can spot where the problem is, however I'm posting this in the hope somebody can spot the bug earlier than me :) Cheers Mark -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
