On Feb 1, 2008 6:38 AM, Tony van der Hoff <[EMAIL PROTECTED]> wrote:
> Meanwhile, and maybe easier to diagnose, I find:
>
> [EMAIL PROTECTED]:~$ sudo ammt -t /dev/nht0 status
> tapedev /dev/nht0 is offline or has no loaded tape.
> /dev/nht0 status failed: Success
>
> Whereas:
>
> [EMAIL PROTECTED]:~$ sudo mt -t /dev/nht0 status
> drive type = Generic SCSI-2 tape
> drive status = 512
> sense key error = 0
> residue count = 0
> file number = 0
> block number = 0
> Tape block size 512 bytes. Density code 0x0 (default).
> Soft error count since last status=0
> General status bits on (4000000):
> WR_PROT
>
> I have attached the strace dumps for all 3 commands.
> Thanks again for your help.
>From the strace, it looks like both applications (ammt and mt) are
making the same syscalls, but getting different results:
mt:
open("/dev/nht0", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFCHR|0660, st_rdev=makedev(37, 128), ...}) = 0
ioctl(3, MGSL_IOCGPARAMS or MTIOCTOP or SNDCTL_MIDI_MPUMODE, 0xbfa50750) = 0
ioctl(3, MGSL_IOCSTXIDLE or MTIOCGET or SNDCTL_MIDI_MPUCMD, 0xbfa50738) = 0
ammt:
open("/dev/nht0", O_RDONLY|O_LARGEFILE) = 3
ioctl(3, MGSL_IOCSTXIDLE or MTIOCGET or SNDCTL_MIDI_MPUCMD, 0xbf884cd8) = 0
It comes from this code in taper-src/output-tape.c:
537 #ifdef GMT_ONLINE
538 if (!GMT_ONLINE(mt.mt_gstat)) {
539 close(ret);
540 fprintf(stderr, "tapedev %s is offline or has no
loaded tape.\n",
541 filename);
542 return -1;
543 }
544 #endif /* GMT_ONLINE */
So I think the only conclusion is that something in your config is
buggy, and MTIOCGET is not returning an "ONLINE" state.
Unfortunately, strace doesn't give us any insight into the contents of
the 'mt' struct.
The new device-src/tape-posix.c does a similar thing:
145 TapeCheckResult tape_is_ready(int fd) {
146 struct mtget get;
147 if (0 == ioctl(fd, MTIOCGET, &get)) {
148 #if defined(GMT_ONLINE) || defined(GMT_DR_OPEN)
149 if (1
150 #ifdef GMT_ONLINE
151 && GMT_ONLINE(get.mt_gstat)
152 #endif
153 #ifdef GMT_DR_OPEN
154 && !GMT_DR_OPEN(get.mt_gstat)
155 #endif
156 ) {
157 return TAPE_CHECK_SUCCESS;
158 } else {
159 return TAPE_CHECK_FAILURE;
160 }
161 #else /* Neither macro is defined. */
162 return TAPE_CHECK_UNKNOWN;
163 #endif
164 } else {
165 return TAPE_CHECK_FAILURE;
166 }
167 }
Neither looks obviously incorrect, but I'm not well-versed in the
posix tape interface. I think the best trick at this point may be to
upgrade your kernel and/or tape drivers, but if you're interested in
getting low-level, you could compile Amanda with debugging symbols
(./configure ... CFLAGS=-g ...) and then run ammt under gdb, break on
tape_tape_open, and investigate the contents of the 'mt' struct. As
is always a frustration with hardware-related questions, this is not
something anyone can investigate on your behalf :(
Another solution may be to just delete lines 537-544, recompile, and
see what happens.
Dustin
--
Storage Software Engineer
http://www.zmanda.com
