[mythtv-users] Mythzmserver DB problems. Was: doesn't start:...

[Hika van den Hoven]

Hoi A.,

Tuesday, April 27, 2021, 5:12:16 AM, you wrote:

> On Tue, Apr 27, 2021 at 01:43:27AM +0100, Paul Harrison wrote:
>>    On 26/04/2021 21:02, A. F. Cano wrote:
>> 
>>      Summary:
>> 
>>  getZMSetting: ZM_SHM_KEY Result: 0x7a6d0000
>>  Shared memory key is: 0x7a6d0000
>>  Failed to get mysql row
>>  ...
>>  Failed to open mmap file [/zm.mmap.2] for monitor: 2 : No such file or directory
>>  Falling back to the legacy shared memory method
>>  Failed to shmget for monitor: 2
>>  ENOENT - no segment exists for the given key
>>  ...
>>  getZMSetting: ZM_PATH_MAP Result:
>>  Memory path directory is:
>> 
>>  I wonder if this ZM_PATH_MAP needs to be set explicitly and if so what
>>  needs to be the value.  Shared memory seems to be the problem.  Or is
>>  this obtained from the mysql row that fails?
>> 
>>    OK thanks for the log I think I see what's happening now.
>> 
>>    In older versions of ZM < 1.32.0 the shared memory path was stored in the
>>    database Config table as setting "ZM_PATH_MAP" but newer version >= 1.32.0
>>    put the ZM_PATH_MAP setting in the
>>    /etc/zm/zm.conf or in /etc/zm/conf.d/01-system-paths.conf config files.
>> 
>>    When mythzmserver starts up it first looks for the ZM_VERSION setting to
>>    figure out which version of ZM we have and if it is >= 1.32.0 it looks for
>>    the ZM_PATH_MAP setting in either of the two *.conf files. If it's not
>>    found then as a last resort looks for the ZM_PATH_MAP setting in the
>>    database which it looks like that setting was removed from the database in
>>    newer versions which is why you get the 'Failed to get mysql row' error
>>    messages. I use 1.34.26 and no longer see that setting in the DB either.
>> 
>>    So basically you need to make sure one of the two *.conf files contains a
>>    setting for ZM_PATH_MAP (the Ubuntu packages I use do this automatically,
>>    I'm guessing the deb_multimedia packages use a different name/location for
>>    the user config file at /etc/zm/conf.d/01-system-paths.conf?)
>> 
>>    My ZM_PATH_MAP setting is in /etc/zm/conf.d/01-system-paths.conf and looks
>>    like this :-
>> 
>>    # Full Path to ZoneMinder's mapped memory files
>>    # The web account user must have full read/write permission to this
>>    folder.
>>    ZM_PATH_MAP=/dev/shm

> Same here.

> $ ls -la /dev/shm
> total 72024
> drwxrwxrwt  2 root     root           80 Apr 26 22:55 ./
> drwxr-xr-x 20 root     root         3780 Apr 23 19:17 ../
> -rw------- 1 postgres postgres    14992 Apr 21 08:05 PostgreSQL.1073826586
> -rw------- 1 www-data www-data 73733672 Apr 26 22:10 zm.mmap.2

> I am a member of groups www-data and video.  I start the front-end as myself.

> This is what's in /etc/group for the relevant groups:

> www-data:x:33:afc
> video:x:44:afc,mythtv,motion,www-data

> Evan after chmod g+rw /etc/shm/zm.mmap.2

> $ ls -l /dev/shm
> total 72024
> -rw------- 1 postgres postgres    14992 Apr 21 08:05 PostgreSQL.1073826586
> -rw-rw---- 1 www-data www-data 73733672 Apr 26 22:10 zm.mmap.2

> The ZM_PATH_MAP is blank:

> getZMSetting: ZM_PATH_MAP Result: 
> Memory path directory is: 

> and the frontend cannot access the shared memory and I only see the test
> pattern.  Maybe it's not a permissions issue, or is it?

> Even after chmod o+rw /dev/shm/zm.mmap.2

> $ ls -l /dev/shm
> total 72024
> -rw------- 1 postgres postgres    14992 Apr 21 08:05 PostgreSQL.1073826586
> -rw-rw-rw- 1 www-data www-data 73733672 Apr 26 22:10 zm.mmap.2

> the ZM_PATH_MAP is still blank, but now I get this: (this is an error
> message from the frontend, not mythzmserver.

>                         ERROR - Cannot get shared memory pointers
> 2021-04-26 22:37:36.565699 E  The server failed to process the command. The error was:-

> repeated a gazillion times while in "show live view", while still only
> seeing the test pattern.  Curiouser and curiouser...

> The conf file says "read/write permission to the folder".  It shouldn't
> be necessary to chmod the file itself, right?

> Even starting the frontend with sudo gives the same result.

> Not sure what else to try next.  Any ideas?

> Thanks!

> Augustine
> _______________________________________________

You should check if that user has access to the folder ánd to the path
leading there (r+x). The easiest way to check is to try reading the
file as that user. If you need write permission, try to echo to a file
in that directory as that user.
   echo test > /dev/shm/test




Tot mails,
  Hika                            mailto:hikavdh at gmail.com

"Zonder hoop kun je niet leven
Zonder leven is er geen hoop
Het eeuwige dilemma
Zeker als je hoop moet vernietigen om te kunnen overleven!"

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