Since a recent burglary I have been using ZoneMinder to provide CCTV security for my house on my Ubuntu 12.04 machine. I noticed earlier today that zoneminder had stopped running over the weekend and when I tried to start the service again, I got the following error:
Starting ZoneMinder: Bareword "ZM_PATH_LOGS" not allowed while "strict subs" in use at /usr/share/perl5/ZoneMinder/Logger.pm line 153.
BEGIN not safe after errors--compilation aborted at /usr/share/perl5/ZoneMinder/Logger.pm line 168.
Compilation failed in require at /usr/share/perl5/ZoneMinder.pm line 34.
BEGIN failed--compilation aborted at /usr/share/perl5/ZoneMinder.pm line 34.
Compilation failed in require at /usr/bin/zmpkg.pl line 37.
BEGIN failed--compilation aborted at /usr/bin/zmpkg.pl line 37.
failure
Looking through the ZoneMinder code I discovered that the error indicated that a configuration variable somehow wasn't set. My first thought was that perhaps a new configuration variable had been added in an upgrade but hadn't been automatically added to the configuration file. So I added a line containing ZM_PATH_LOGS to /etc/zm/zm.conf but now when I tried to start zoneminder, I received a similar (but different error):
Starting ZoneMinder: Bareword "ZM_USE_DEEP_STORAGE" not allowed while "strict subs" in use at /usr/share/perl5/ZoneMinder/General.pm line 207.
BEGIN not safe after errors--compilation aborted at /usr/share/perl5/ZoneMinder/General.pm line 226.
Compilation failed in require at /usr/share/perl5/ZoneMinder.pm line 35.
BEGIN failed--compilation aborted at /usr/share/perl5/ZoneMinder.pm line 35.
Compilation failed in require at /usr/bin/zmpkg.pl line 37.
BEGIN failed--compilation aborted at /usr/bin/zmpkg.pl line 37.
failure
I added a line for this then another similar (but different) error appeared! Clearly this approach isn't correct. So I logged into mysql and had a poke around:
mysql -u XXX -p
mysql> show databases;
mysql> use zm;
mysql> show tables;
+----------------+
| Tables_in_zm |
+----------------+
| Config |
| ControlPresets |
| Controls |
| Devices |
| Events |
| Filters |
| Frames |
| Groups |
| Logs |
| MonitorPresets |
| Monitors |
| States |
| Stats |
| TriggersX10 |
| Users |
| ZonePresets |
| Zones |
+----------------+
17 rows in set (0.00 sec)
mysql> select * from Config;
0 rows in set (0.00 sec)
Like in iPhone adverts, the above sequence is shortened. But the surprising result appears at the end: there are no lines in the Config table! This must be the culprit preventing ZoneMinder from starting.
Its not clear how this config table has been reset, as I don't recall updating the ZoneMinder packages recently, so I don't think its a botched database upgrade. I have restarted the machine that it runs on a couple of times over the weekend so perhaps the database got corrupted at shutdown, though I can't find any mysql logs complaining about this. In conclusion, I don't know how it happened! But if it happens again all the info is here.
To resolve this, I download the ubuntu package for zoneminder and had a look in the postinst install script to see how it initialised the database. It turns out there is an sql file at /usr/share/zoneminder/db/zm_create.sql which is applied at package installation. I edited this file and removed all lines that didn't affect the Config table and applied it manually.
Finally zoneminder started up (albeit without my configurations)! After reconfiguring zoneminder, I noticed in ZoneMinder's log database the following entry:
Config mismatch, expected 218 items, read 0. Try running 'zmupdate.pl -f' to reload config.
If this happens again, perhaps 'zmupdate.pl -f' is sufficient to fix it, instead of error-prone sql hacking. (update: according to commenters this does not work!)
And the moral of the story is: always backup your databases!
So, how do we get rid of it? We go to the chromium settings via the triple line menu, then we choose Manage Search Engines, and observe that there are two "google" search engines. One has a url similar to google.com/cse (for custom search engine) and is marked as the default. All we do is set one of the other search engines as default, then click the X to delete Mint's one.
