[Samba] 'samba-tool dbcheck' reports only a "Bus error"

Tue Oct 27 13:00:50 UTC 2015

Andrew, don't look any further into this matter. I finally found this on 
the local console, definitely hardware related:

ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
ata1.00: BMDMA stat 0x25
ata1.00: failed command: READ DMA
ata1.00: cmd c8/00:00:28:81:18/00:00:00:00:00/e0 tag 5 dma 131072 in
          res 51/40:1f:09:82:18/00:00:00:00:00/e0 Emask 0x9 (media error)
ata1.00: status: { DRDY ERR }
ata1.00: error: { UNC }

I didn't see this earlier, because I used to restart the server whenever 
I went over to the physical machine. And the file system check I 
enforced on system reboot reported "clean".

Sorry for the fuss.

Ole

Am 27.10.2015 um 11:40 schrieb Ole Traupe:
> Andrew, thank you for your help! Could a "Bus error" be related to a 
> hardware problem? Never seen it before.
>
> Anyways, here is the output of my debugging session (I hope I did 
> everything correctly):
>
>
>
> [root at server bin]# gdb --args python /usr/local/samba/bin/samba-tool 
> dbcheck
> GNU gdb (GDB) Red Hat Enterprise Linux (7.2-75.el6)
> Copyright (C) 2010 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later 
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show 
> copying"
> and "show warranty" for details.
> This GDB was configured as "i686-redhat-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> Reading symbols from /usr/bin/python...(no debugging symbols 
> found)...done.
> Missing separate debuginfos, use: debuginfo-install 
> python-2.6.6-52.el6.i686
> (gdb) run
> Starting program: /usr/bin/python /usr/local/samba/bin/samba-tool dbcheck
> [Thread debugging using libthread_db enabled]
> Detaching after fork from child process 26458.
> Detaching after fork from child process 26460.
>
> Program received signal SIGBUS, Bus error.
> 0x00378296 in __memcpy_ia32 () from /lib/libc.so.6
> (gdb) backtrace
> #0  0x00378296 in __memcpy_ia32 () from /lib/libc.so.6
> #1  0x0051da2b in py_ldb_schema_format_value () from 
> /usr/local/samba/lib/python2.6/site-packages/ldb.so
> #2  0x006efeca in tdb_rec_read () from 
> /usr/local/samba/lib/private/libtdb.so.1
> #3  0x006eb02d in tdb_next_lock () from 
> /usr/local/samba/lib/private/libtdb.so.1
> #4  0x006eb3dc in tdb_traverse_internal () from 
> /usr/local/samba/lib/private/libtdb.so.1
> #5  0x006eb499 in tdb_traverse_read () from 
> /usr/local/samba/lib/private/libtdb.so.1
> #6  0x0270b562 in ltdb_search_full () from 
> /usr/local/samba/lib/ldb/tdb.so
> #7  0x0270b8b4 in ltdb_search () from /usr/local/samba/lib/ldb/tdb.so
> #8  0x02709f1e in ltdb_callback () from /usr/local/samba/lib/ldb/tdb.so
> #9  0x005072a3 in tevent_common_loop_timer_delay () from 
> /usr/local/samba/lib/private/libtevent.so.0
> #10 0x005095dd in epoll_event_loop_once () from 
> /usr/local/samba/lib/private/libtevent.so.0
> #11 0x0050664a in std_event_loop_once () from 
> /usr/local/samba/lib/private/libtevent.so.0
> #12 0x00501533 in _tevent_loop_once () from 
> /usr/local/samba/lib/private/libtevent.so.0
> #13 0x0054d95a in ldb_wait () from 
> /usr/local/samba/lib/private/libldb.so.1
> #14 0x0051dd87 in py_ldb_search () from 
> /usr/local/samba/lib/python2.6/site-packages/ldb.so
> #15 0x00193b28 in PyCFunction_Call () from /usr/lib/libpython2.6.so.1.0
> #16 0x001eddbb in PyEval_EvalFrameEx () from /usr/lib/libpython2.6.so.1.0
> #17 0x001ee98a in PyEval_EvalCodeEx () from /usr/lib/libpython2.6.so.1.0
> #18 0x001eca83 in PyEval_EvalFrameEx () from /usr/lib/libpython2.6.so.1.0
> #19 0x001ee98a in PyEval_EvalCodeEx () from /usr/lib/libpython2.6.so.1.0
> #20 0x00181f27 in ?? () from /usr/lib/libpython2.6.so.1.0
> #21 0x001585cd in PyObject_Call () from /usr/lib/libpython2.6.so.1.0
> #22 0x001eba5b in PyEval_EvalFrameEx () from /usr/lib/libpython2.6.so.1.0
> #23 0x001ee98a in PyEval_EvalCodeEx () from /usr/lib/libpython2.6.so.1.0
> #24 0x00181e28 in ?? () from /usr/lib/libpython2.6.so.1.0
> #25 0x001585cd in PyObject_Call () from /usr/lib/libpython2.6.so.1.0
> #26 0x001eba5b in PyEval_EvalFrameEx () from /usr/lib/libpython2.6.so.1.0
> #27 0x001ee98a in PyEval_EvalCodeEx () from /usr/lib/libpython2.6.so.1.0
> #28 0x00181e28 in ?? () from /usr/lib/libpython2.6.so.1.0
> #29 0x001585cd in PyObject_Call () from /usr/lib/libpython2.6.so.1.0
> #30 0x001eba5b in PyEval_EvalFrameEx () from /usr/lib/libpython2.6.so.1.0
> #31 0x001ee98a in PyEval_EvalCodeEx () from /usr/lib/libpython2.6.so.1.0
> #32 0x001eeaa4 in PyEval_EvalCode () from /usr/lib/libpython2.6.so.1.0
> #33 0x00208e6c in ?? () from /usr/lib/libpython2.6.so.1.0
> #34 0x00208f33 in PyRun_FileExFlags () from /usr/lib/libpython2.6.so.1.0
> #35 0x0020a5b1 in PyRun_SimpleFileExFlags () from 
> /usr/lib/libpython2.6.so.1.0
> #36 0x0020ae62 in PyRun_AnyFileExFlags () from 
> /usr/lib/libpython2.6.so.1.0
> #37 0x0021776b in Py_Main () from /usr/lib/libpython2.6.so.1.0
> #38 0x080485c8 in main ()
>
>
>
>
>
> Am 27.10.2015 um 06:40 schrieb Andrew Bartlett:
>> On Sun, 2015-10-25 at 16:14 +0100, Ole Traupe wrote:
>>> For a few days now my primary DC has some issues. I can create users
>>> without a problem. But when I try to alter the group membership of
>>> users, one of my samba processes crashes (the one listening to the
>>> LDAP
>>> related ports: 389, 636, 3268, 3269).
>>>
>>> Also, when I start my backup DC, a few seconds later another process
>>> crashes on the primary DC (the RPC related listening to 135 and
>>> 1024).
>>>
>>> I haven't made any updates to OS or Samba (still 4.2.2), but I have
>>> adjusted some UIDs and GIDs recently.
>>>
>>> Despite "log level = 3", the "log.samba" gives only this,
>>>
>>> [2015/10/22 19:05:46.500567,  0] ../lib/util/fault.c:78(fault_report)
>>> ===============================================================
>>> [2015/10/22 19:05:46.515490,  0] ../lib/util/fault.c:79(fault_report)
>>>     INTERNAL ERROR: Signal 7 in pid 3794 (4.2.2)
>>>     Please read the Trouble-Shooting section of the Samba HOWTO
>>> [2015/10/22 19:05:46.515633,  0] ../lib/util/fault.c:81(fault_report)
>>> ===============================================================
>>> [2015/10/22 19:05:46.515732,  0]
>>> ../lib/util/fault.c:151(smb_panic_default)
>>>     PANIC: internal error
>>>
>>> while the trouble shooting page directs me to the log files. ;)
>>>
>>> When I try a 'samba-tool dbcheck' on the PDC, I get the message "Bus
>>> error". Nothing more. When I do it on the BDC, the check runs through
>>> without errors. The sam.ldb on the BDC is in an earlier state because
>>> replication isn't working any more.
>>>
>>> What does "Bus error" mean? Have I messed up my data base? Or is it
>>> something else?
>> What I suggest is running samba-tool under gdb --args, and then getting
>> a backtrace.  That will give a clue to where in the C code we are
>> faulting (if that is the case), and so what the likely issue is.  We
>> can then proceed to fixing both.
>>
>> gdb --args python /usr/local/bin/samba-tool
>>
>> Andrew Bartlett
>>
>
>