========================================================================
Error reading attached process's symbol file.
: No such file or directory.
Reading symbols from /lib/x86_64-linux-gnu/libdl.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/x86_64-linux-gnu/libdl.so.2
Reading symbols from /lib/libdevmapper-event.so.1.02.1...(no debugging symbols found)...done.
Loaded symbols for /lib/libdevmapper-event.so.1.02.1
Reading symbols from /lib/libreadline.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libreadline.so.6
Reading symbols from /lib/libdevmapper.so.1.02.1...(no debugging symbols found)...done.
Loaded symbols for /lib/libdevmapper.so.1.02.1
Reading symbols from /lib/x86_64-linux-gnu/libudev.so.0...(no debugging symbols found)...done.
Loaded symbols for /lib/x86_64-linux-gnu/libudev.so.0
Reading symbols from /lib/x86_64-linux-gnu/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/x86_64-linux-gnu/libc.so.6
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib/libtinfo.so.5...(no debugging symbols found)...done.
Loaded symbols for /lib/libtinfo.so.5
Reading symbols from /lib/x86_64-linux-gnu/libselinux.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib/x86_64-linux-gnu/libselinux.so.1
Reading symbols from /lib/x86_64-linux-gnu/librt.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib/x86_64-linux-gnu/librt.so.1
Reading symbols from /lib/x86_64-linux-gnu/libpthread.so.0...(no debugging symbols found)...done.
[Thread debugging using libthread_db enabled]
Loaded symbols for /lib/x86_64-linux-gnu/libpthread.so.0
Error reading attached process's symbol file.
: No such file or directory.
0x00007f636430a797 in semop () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) where
#0  0x00007f636430a797 in semop () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f63647dd75c in dm_udev_wait () from /lib/libdevmapper.so.1.02.1
#2  0x0000000000476d5f in ?? ()
#3  0x0000000000f19ce0 in ?? ()
#4  0x0000000000000001 in ?? ()
#5  0x0000000000000000 in ?? ()
(gdb) quit
A debugging session is active.

        Inferior 1 [process 301] will be detached.

Quit anyway? (y or n) y
Detaching from program: /sbin/lvm, process 301

========================================================================
root@sergelap:~# !str
strace -f -p 301
Process 301 attached - interrupt to quit
semop(32768, {{0, 0, 0}}, 1^C <unfinished ...>
Process 301 detached


========================================================================
root@sergelap:~# ipcs

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status      

------ Semaphore Arrays --------
key        semid      owner      perms      nsems     
0x0d4d79de 32768      root       600        1         
0x00000000 98305      www-data   600        1         

------ Message Queues --------
key        msqid      owner      perms      used-bytes   messages    

========================================================================
root@sergelap:~# ipcs -s 0x0d4d79de -i 32768

Semaphore Array semid=32768
uid=0    gid=0   cuid=0  cgid=0
mode=0600, access_perms=0600
nsems = 1
otime = Sun Oct  9 09:26:38 2011  
ctime = Sun Oct  9 09:26:38 2011  
semnum     value      ncount     zcount     pid       
0          1          0          1          301