Fatal error: Call to undefined function pcntl_fork() in /path/blah.php on line 5

The fix requires recompiling php with –enable-pcntl Fortunately cpanel offers the Easy Apache script. The bad part is that it doesn’t have an option for pcntl. So you have to specify it as a custom compile time option. Edit (or create – for PHP5) and add /var/cpanel/easy/apache/rawopts/all_php5

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--enable-pcntl

On one line

Then rebuild Easy Apache.

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[root@host ~]# mysql -u user -pPassword database < database.sql
Enter password:
ERROR 1153 (08S01) at line 53: Got a packet bigger than 'max_allowed_packet' bytes

It’s easily fixable. The default is probably 16M, I added the following in /etc/my.cnf

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max_allowed_packet=32M

And restarted mysql (depending on your distro you will do this differently):

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service mysqld restart

So, I had to set-up master-slave replication. Here’s how you do it:

Why would one want to set-up this? Easy.

1)Spread the read load across multiple servers:  you can use the MySQL master for writing (inserts, updates) and the slave(s) for reading (SELECT) This should speed up things nicely for your application.

2)Do the backups from the slave. You might have noticed that backing-up, especially big databases, slows things down. That happens because mysqldump locks tables as it reads them. This can slow a big site or even takes it down from a few seconds to a few minute. Reading from the slave affects nothing. You can even stop the slave, read the /var/lib/mysql folder and start it back.

Following are the steps on how to set it up, but first let’s not a few assumptions. Also please note that this sets up only the basic things. Many more settings can be tweaked to improve MySQL performance.

Master server ip: 192.168.0.1
Slave server ip: 192.168.0.2
Slave username: slaveusr
Slave pw: slavepass
Your data directory is: /var/lib/mysql

Add the following lines in your master my.cnf file under [mysqld] section:

# master my.cnf
server-id = 1
relay-log = /var/lib/mysql/mysql-relay-bin
relay-log-index = /var/lib/mysql/mysql-relay-bin.index
log-error = /var/lib/mysql/mysql.err
master-info-file = /var/lib/mysql/mysql-master.info
relay-log-info-file = /var/lib/mysql/mysql-relay-log.info
datadir = /var/lib/mysql
log-bin = /var/lib/mysql/mysql-bin
# end master 


The following settings are for the slave’s my.cnf under the same [mysqld] section:

# slave's my.cnf
server-id = 2
relay-log = /var/lib/mysql/mysql-relay-bin
relay-log-index = /var/lib/mysql/mysql-relay-bin.index
log-error = /var/lib/mysql/mysql.err
master-info-file = /var/lib/mysql/mysql-master.info
relay-log-info-file = /var/lib/mysql/mysql-relay-log.info
datadir = /var/lib/mysql
# end slave settings

Restart both mysql instances after changing the settings in my.cnf

Create the slave user on master server:
mysql> grant replication slave on *.* to slaveusr@'10.0.0.2' identified by 'slavepass';

Dump the full data and copy it (scp, etc.) to the slave

mysqldump -u root -pROOTPASS --all-databases --single-transaction --master-data=1 > masterdump.sql

import this dump on the slave server:

mysql -u root -pROOTPASS < masterdump.sql

After dump is imported go in to mysql client by typing mysql. Let us tell the slave which master to connect to and what login/password to use:
mysql> CHANGE MASTER TO MASTER_HOST='192.168.0.1', MASTER_USER='slaveusr', MASTER_PASSWORD='slavepass';

Start the slave:
mysql> start slave;

Check the status on the slave:
mysql> show slave status\G

The last row will tell how many seconds the slave runs behind the master. No worries if it’s not 0, it should catch up quickly (at that time it will show Seconds_Behind_Master: 0) If it reads NULL, maybe the slave is not started (you can start by typing: start slave) or it could be that there is a problem(shows up in Last_errno: and Last_error under show slave status).

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### by SV for i2600k temperature
/sbin/modprobe coretemp
/sbin/modprobe pkgtemp

Now sensors report the temperatures.

One of the above broken everything (I started seeing _digikam_root_tag) and some of my tags were doubled. So all in all I wanted to delete them all:

• Remove your collection from digikam
• Drop all tables from the digikam database
• Remove all .xmp files. In the folder containing your collection:
  find . -name *.xmp -exec rm {} \;
• Remove all embedded xmp tags (again in the folder containing you collection)
  exiftool -r -P -xmp:TagsList= -xmp:LastKeywordXMP= -xmp:HierarchicalSubject= -xmp:Subject= -iptc:Keywords= *

DON’T FOLLOW THIS BLINDLY

This is just a sketch of the process. If you don’t understand what are you doing don’t do it! I also kept all .original files exiftool generated, just in case I discover something later on.

Here’s how to unpack a .deb to obtain both scripts and files:

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cd /tmp/somefolder
ar x somepackage.deb

In order to log dropped packets on the INPUT chain I replaced this:

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-A INPUT -i eth0 -j REJECT --reject-with icmp-host-prohibited

with this

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-N LOGDROP
-A LOGDROP -i eth0 -j LOG
-A LOGDROP -i eth0 -j REJECT --reject-with icmp-host-prohibited
-A INPUT -i eth0 -j LOGDROP

Of course you can use DROP instead of REJECT –reject-with icmp-host-prohibited

Enabling the slow query log

MySQL prior to 5.1.0 requires adding a setting to the MySQL my.cnf file and restart the mysql daemon in order to log slow queries; from MySQL 5.1.0 onwards you can also change this dynamically without having to restart.

To make the setting permanent every time you start MySQL (or you have a version prior to 5.1.0) add (ow uncomment) the following in my.cnf (usually /etc/my.cnf or /etc/mysql/my.cnf)

log_slow_queries = /var/log/mysql/mysql-slow.log

You can skip the path or leave it blank completely and mysql will create the log in the default location. The default is to log the queries into a file in the MySQL data directory.

To enable or disable the setting dynamically in MySQL 5.1.0 run the following query to enable it:

set log_slow_queries = ON;

and to disable it:

set log_slow_queries = OFF;

Changing the long query time

You can also set how long a query needs to take before it’s considered a “long” query. The default is 10 seconds. I usually like to set it lower:

To change it to 5 seconds add in my.cnf:

long_query_time = 5

This can be changed dynamically in MySQL 5.0.0+ (and possibly earlier versions) by running the following query:

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set global long_query_time = 5;

This will only work for new connections; any connections which have already been established will continue to use the old setting. Once the user disconnects and reconnects their new connection will use the new setting.

Errors you can get applying these settings dynamically

If the following error message appears when attempting to change the log_slow_queries setting dynamically means you are using a version of MySQL that does not support changing the setting dynamically:

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ERROR 1193 (HY000): Unknown system variable 'log_slow_queries'

The long_query_time value must be integer; if it’s not (e.g. you set long_query_time = 2.5;) then you’ll see this error:

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#1232 - Incorrect argument type to variable 'long_query_time'

Note also that if you set the long_query_time to 0 it will not fail, but the actual setting applied will be 1 and not 0.

Unfortunately trying to run the setup on Slackware gives the errors regarding to

/…/bin/eagle: error while loading shared libraries: libssl.so.1.0.0: cannot open shared object file: No such file or directory

libssl.so.1.0.0 and libcrypto.so.1.0.0

I run a multilib setup so that’s not it. It turns that all I had to do was:

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cd /lib
ln -s libssl.so.0.9.8 libssl.so.1.0.0
ln -s libcrypt-2.14.1.so libcrypto.so.1.0.0

in /lib

Hope that helps.

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perl -pi -e 's/old_text/new_text/g' *.conf

This line replaces old_text with new_text in all the .conf files in the current folder. Of course you can use regular expressions.