Re: [Bacula-devel] Possible FreeBSD pthreads bug

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I thought I sent this yesterday, then resent it this morning, encrypted. Sorry about that.  Resending now.

> On May 24, 2015, at 2:19 PM, Dan Langille <da...@la...> wrote:
> 
> 
>> On May 20, 2015, at 3:37 AM, Kern Sibbald <ke...@si...> wrote:
>> 
>> Hello Dan,
>> 
>> We recently discussed a problem with logical end of tape markers on the
>> newest FreeBSD system.  That reminded me of the previous time we had
>> problems, and it took us a very long time to find the problem 3-4 months
>> if I remember right.
>> 
>> Anyway, here is your email on the subject and the source of the file
>> that we used to diagnose the problem.  I would be a bit surprised if the
>> current problem is the same thing, but it is probably worth trying.  I
>> haven't tried compiling the program recently so let me know if you have
>> problems.
>> 
>> Best regards,
>> Kern
>> 
>> PS: It took me a long time to find these attachments because I thought
>> they were in the test environment, but it looks like I committed them to
>> the bacula/platforms/freebsd directory.
> 
> Compiling on FreeBSD 9.3:
> 
> $   c++ -g -O2 -Wall -c tapetest.c
> tapetest.c: In function 'void rrcmd()':
> tapetest.c:327: warning: deprecated conversion from string constant to 'char*'
> tapetest.c: At global scope:
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c:526: warning: deprecated conversion from string constant to 'char*'
> tapetest.c: In function 'void do_tape_cmds()':
> tapetest.c:535: warning: deprecated conversion from string constant to 'char*'
> 
> $   c++ -g -O2 -Wall tapetest.o -o tapetest
> $
> 
> 
> $ sudo ./tapetest /dev/sa0
> *rewind
> Rewound /dev/sa0
> *rawfill
> Begin writing blocks of 64512 bytes.
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> weof_dev
> ioctl MTWEOF error on /dev/sa0. ERR=Input/output error.
> Bad status from weof -1. ERR=Input/output error
> Write failed.  Last block written=52274. stat=24576 ERR=No such file or directory
> *
> 
> From /var/log/messages:
> 
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): WRITE FILEMARKS(6). CDB: 10 00 00 00 01 00
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): CAM status: SCSI Status Error
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): SCSI status: Check Condition
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): SCSI sense: MEDIUM ERROR asc:c,0 (Write error)
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): Command Specific Info: 0xca7b
> May 24 18:17:57 knew kernel: (sa0:sym0:0:1:0): Error 5, Retries exhausted
> 

Sorry.  I thought was was sent yesterday.

The above was on a tape such as the one which raised the original issue.

Next, I tried another previously unused tape.  With the pthreads option, I got:

...
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
weof_dev
Wrote EOF to /dev/sa0
Write failed.  Last block written=1580354. stat=0 ERR=No such file or directory
*

Then I stopped overnight.  The next day, after other backups to tape, i loaded up the tape used above

 $ sudo ./tapetest /dev/sa0
*rewind
Rewound /dev/sa0ve.
*scan
Starting scan at file 0
1580354 blocks of 64512 bytes in file 0
End of File mark.
End of File mark.
End of tape
Total files=1, blocks=1580354, bytes = -1127417856
*

My conclusion: good tapes, such as the one above, just work.  Bad tapes, such as the one at the top of this post, fail.  They're just bad tapes.

Kern: what's your conclusion?  I'm happy to run more tests.

—
Dan Langille
http://langille.org/