I had a similiar problem and the solution was this...
The Sony ATAPI SDX-420c tape backup drive was on a IDE cable shared with the CDROM drive. Removing the CDROM drive from the cable immediately resolved all problems.
dmesg reported the following when both the CDROM & Sony ATAP tape backup unit were connected.
Aug 7 17:30:49 tex kernel: ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
Aug 7 17:30:49 tex kernel: hdc: Compaq CRD-8400B, ATAPI CD/DVD-ROM drive
Aug 7 17:30:49 tex rc: Starting lm_sensors: succeeded
Aug 7 17:30:49 tex kernel: hdd: �������������������, ATAPI TAPE drive
Aug 7 17:30:49 tex kernel: ide1 at 0x170-0x177,0x376 on irq 15
Aug 7 17:30:49 tex kernel: hda: max request size: 128KiB
Aug 7 17:30:49 tex kernel: hda: 156301488 sectors (80026 MB) w/8192KiB Cache, CHS=65535/16/63, UDMA(66)
Aug 7 17:30:49 tex kernel: hda: cache flushes not supported
Aug 7 17:30:49 tex kernel: hda: hda1 hda2 hda3
Aug 7 17:30:49 tex kernel: hdb: max request size: 1024KiB
Aug 7 17:30:49 tex kernel: hdb: 390721968 sectors (200049 MB) w/8192KiB Cache, CHS=24321/255/63, UDMA(66)
Aug 7 17:30:49 tex kernel: hdb: cache flushes supported
Aug 7 17:30:49 tex kernel: hdb: hdb1
Aug 7 17:30:49 tex kernel: hdc: ATAPI 40X CD-ROM drive, 128kB Cache, DMA
Aug 7 17:30:49 tex kernel: Uniform CD-ROM driver Revision: 3.20
Aug 7 17:30:49 tex kernel: ide-tape: ht0: I/O error, pc = 12, key = 0, asc = c0, ascq = 81
Aug 7 17:30:49 tex kernel: ide-tape: hdd <-> ht0: ���� �������� rev ��
Aug 7 17:30:49 tex kernel: ide-tape: ht0: I/O error, pc = 1a, key = 0, asc = c0, ascq = 81
Aug 7 17:30:49 tex kernel: ide-tape: ht0: I/O error, pc = 1a, key = 0, asc = c0, ascq = 81
Aug 7 17:30:49 tex kernel: ide-tape: decreasing stage size
Aug 7 17:30:49 tex last message repeated 7 times
Aug 7 17:30:49 tex autofs: automount startup succeeded
Aug 7 17:30:49 tex kernel: ide-tape: decreasing stage size
Aug 7 17:30:49 tex kernel: ide-tape: hdd <-> ht0: 144KBps, 167*48kB buffer, 2646kB pipeline, 362ms tDSC
After removing the CDROM dmesg reports this:
hdc: SONY SDX-420C, ATAPI TAPE drive
ide1 at 0x170-0x177,0x376 on irq 15
Probing IDE interface ide2...
Probing IDE interface ide3...
Probing IDE interface ide4...
Probing IDE interface ide5...
hda: max request size: 128KiB
hda: 156301488 sectors (80026 MB) w/8192KiB Cache, CHS=65535/16/63, UDMA(66)
hda: cache flushes not supported
hda: hda1 hda2 hda3
hdb: max request size: 1024KiB
hdb: 390721968 sectors (200049 MB) w/8192KiB Cache, CHS=24321/255/63, UDMA(66)
hdb: cache flushes supported
hdb: hdb1
ide-tape: hdc <-> ht0: SONY SDX-420C rev 0103
ide-tape: hdc: overriding capabilities->speed (assuming 650KB/sec)
ide-tape: hdc: overriding capabilities->max_speed (assuming 650KB/sec)
ide-tape: decreasing stage size
ide-tape: decreasing stage size
ide-tape: decreasing stage size
ide-tape: hdc <-> ht0: 650KBps, 62*32kB buffer, 6336kB pipeline, 100ms tDSC, DMA
We also had to compile the kernel with ide-tape as a module, since the standard Fedora kernel does not include it.
And change /etc/grub.conf as follows
title Fedora Core (2.6.12)
root (hd0,0)
kernel /vmlinuz-2.6.12 ro root=LABEL=/ rhgb quiet hdc=ide-tape
initrd /initrd-2.6.12.img
And finally, changed /etc/rc.local to create the devices.
echo "Loading IDE tape module"
modprobe ide-tape
echo "Creating tape devices"
#Rewind on close
mknod /dev/ht0 c 37 0
#No rewind on close device
mknod /dev/nht0 c 37 128
chmod 666 /dev/ht0
chmod 666 /dev/nht0
ln -s /dev/ht0 /dev/tape
ln -s /dev/nht0 /dev/tapenorewind
And it all works fantastically now. Hope these tips help someone resolve this issue.
Cheers
Justin Freeman
http://www.agileware.net
http://blog.agileware.net