Posts Tagged ‘debian server’

How to fix “ERROR 1577 (HY000) at line 1: Cannot proceed because system tables used by Event Scheduler were found damaged at server start”

Saturday, May 12th, 2012

After migrating databases data from FreeBSD MySQL 5.0.83 server to a Debian Squeeze Linux MySQL version 5.1.61, below is a mysql –version issued on both the FreeBSD and the Debian servers

freebsd# mysql --version
mysql Ver 14.12 Distrib 5.0.83, for portbld-freebsd7.2 (i386) using 5.2

debian:~# mysql --version
mysql Ver 14.14 Distrib 5.1.61, for debian-linux-gnu (i486) using readline 6.1

The data SQL dump from the FreeBSD server was dumped with following command arguments:

freebsd# mysqldump --opt --allow-keywords --add-drop-table --all-databases -u root -p > complete_db_dump.sql

Then I used sftp to transfer complete_db_dump.sql dump to the a brand new installed latest Debian Squeeze 6.0.2. The Debian server was installed using a "clean Debian install" without graphical environment with CD downloaded from debian.org's site.

On the Debian machine I imported the dump with command:

debian:~# mysq -u root -p < complete_db_dump.sql

Right After the dump was imported I re-started SQL server which was previously installed with:

debian:~# apt-get install mysql-server
The error I got after restarting the mysql server:

debian:~# #/etc/init.d/mysql restart

was:

ERROR 1577 (HY000) at line 1: Cannot proceed because system tables used by Event Scheduler were found damaged at server start
ERROR 1547 (HY000) at line 1: Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted

This error cost me a lot of nerves and searching in google to solve. It took me like half an hour of serious googling ,until I finally found the FIX!!!:

debian:~# mysql_upgrade -u root -h localhost -p --verbose --force
Enter password:
Looking for 'mysql' as: mysql
Looking for 'mysqlcheck' as: mysqlcheck
Running 'mysqlcheck' with connection arguments: '--port=3306' '--socket=/var/run/mysqld/mysqld.sock' '--host=localhost'
Running 'mysqlcheck' with connection arguments: '--port=3306' '--socket=/var/run/mysqld/mysqld.sock' '--host=localhost'
bible.holy_bible OK
bible.holybible OK
bible.quotes_meta OK

Afterwards finally I had to restart the mysql server once again in order to finally get rid of the shitty:

ERROR 1547 (HY000) at line 1: Column count of mysql.proc is wrong. Expected 20, found 16. The table is probably corrupted error!

debian:~# /etc/init.d/mysql restart
Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

This solved the insane Column count of mysql.proc is wrong. Expected 20, found 16 once and for all!

Before I came with this fix I tried all kind of forum suggested fixes like:

debian:~# mysql_upgrade -u root -p
Looking for 'mysql' as: mysql
Looking for 'mysqlcheck' as: mysqlcheck
This installation of MySQL is already upgraded to 5.1.61, use --force if you still need to run mysql_upgrade

debian:~# mysql_upgrade -p
Looking for 'mysql' as: mysql
Looking for 'mysqlcheck' as: mysqlcheck
This installation of MySQL is already upgraded to 5.1.61, use --force if you still need to run mysql_upgrade

And few more, none of them worked the only one that worked was:

debian:~# #mysql_upgrade -u root -h localhost -p --verbose --force

I have to say big thanks to Mats Lindth wonderful blog post which provided me with the solution.

It seems, since Oracle bought the Community edition of MySQL thinks with this database server are getting more and more messy and backwards incompatible day by day.
Lately, I'm experiencing too much hassles with MySQL version incompitabilities. Maybe I should think for migrating permanently to Postgre …

By the way the ERROR 1547 (HY000) at line 1: Column count of mysql.proc is wrong. is most probably caused of some kind of password hashing incompitability between the password hashing between the BSD and Debian SQL versions, as mysql -u root -p < dump.sql, does override default stored user passwords in the mysql database tables… Such password, hashing issues were common in prior MySQL 4 to MySQL 5 migrations I've done, however since MySQL 5+ is already storing its password strings encrypted with md5 encryption I wonder why on earth this mess happens ….
 

How to automatically reboot (restart) Debian GNU Lenny / Squeeze Linux on kernel panic, some general CPU overload or system crash

Monday, June 21st, 2010

If you are a system administrator, you have probably wondered at least once ohw to configure your Linux server to automatically reboot itself if it crashes, is going through a mass CPU overload, e.g. the server load average “hits the sky”.
I just learned from a nice article found here that there is a kernel variable which when enabled takes care to automatically restart a crashed server with the terrible Kernel Panic message we all know.

The variable I’m taking about is kernel.panic for instance kernel.panic = 20 would instruct your GNU Linux kernel to automatically reboot if it experiences a kernel panic system crash within a time limit of 20 seconds.

To start using the auto-reboot linux capabilities on a kernel panic occurance just set the variable to /etc/sysctl.conf

debian-server:~# echo 'kernel.panic = 20' >> /etc/sysctl.conf

Now we will also have to enable the variable to start being use on the system, so execute:

debian-server:~# sysctl -p There you go automatic system reboots on kernel panics is now on.
Now to further assure yourself the linux server you’re responsible of will automatically restart itself on a emergency situation like a system overload I suggest you check Watchdog

You might consider checking out this auto reboot tutorial which explains in simple words how watchdog is installed and configured.
On Debian installing and maintaining watchdog is really simple and comes to installing and enabling the watchdog system service, right afteryou made two changes in it’s configuration file /etc/watchdog.conf

To do so execute:

debian-server:~# apt-get install watchdog
debian-server:~# echo "file = /var/log/messages" >> /etc/watchdog.conf
debian-server:~# echo "watchdog-device = /dev/watchdog" >> /etc/watchdog.conf

Well that should be it, you might also need to load some kernel module to monitor your watchdog.
On my system the kernel modules related to watchdog are located in:

/lib/modules/2.6.26-2-amd64/kernel/drivers/watchdog/
If not then you should certainly try the software watchdog linux kernel module called softdog , to do so issue:
debian-server:~# /sbin/modprobe softdog

It’s best if you load the module while the softdog daemon is disabled.
If you consider auto loadig the softdog software watchdog kernel driver you should exec:

debian-server:~# echo 'softdog' >> /etc/modules

Finally a start of the watchdog is necessery:

 


debian-server:~# /etc/init.d/watchdog start
Stopping watchdog keepalive daemon....
Starting watchdog daemon....

That should be all your automatic system reboots should be now on! 🙂

Installing usual Software Tools and Development header files and libraries on a newly installed Debian Server

Thursday, February 11th, 2010

Today I start my work as a system administrator for a new IT company.
My first duties include configuration and installation of some usual programs
used in everyday's sys admin job.
In that manner of thoughts I have long ago realized there is a common group of
tools and software I had to install on almost each and every new configured
Debian GNU / Linux running Server.
Here is a list of packages I usually install on new Debian systems,
even though this exact commands are expected to be executed on Debian (5.0) Lenny
I believe they are quite accurate for Debian Testing and Debian Testing/Unstable,
bleeding edge distributions.
Before I show you the apt-get lines with all the packages, I would advice you to install
and use netselect-apt to select the fastest Debian package mirror near you
So to install and use run the following commands;

aptitude install netselect-apt
netselect-apt -n lenny

Now as netselect-apt would have tested for the fastest mirror and created sources.list
file in your current directory, open the sources.list file and decide what should enter your
official /etc/apt/sources.list file or in other words merge the two files as you like.
Good, now as we have a fast mirror to download our packages let's continue further with the
packages to install.
Excecute the following command to install some of the basic tools and packages:

# install some basic required tools, software and header files
debian-server:~# apt-get install tcpdump mc ncurses-dev htop iftop iptraf nmap tcpdump apache2 apachetop
mysql-server-5.0 phpmyadmin vnstat rsync traceroute tcptrace e2fsprogs hddtemp finger mtr-tiny
netcat screen imagemagick flex snort mysql-server-5.0 sysstat lm-sensors alien rar unrar util-linux curl
vim lynx links elinks sudo autoconf gcc build-essential dpkg-dev webalizer awstats

Herein I'll explain just a few of the installed package and their install
purpose,as they could be unknown to some of the people out there.

apachetop - monitors apache log file in real time similar to gnu top
iftop - display bandwidth usage on selected interface interactively
vnstat - show inbound & outbound traffic usage on selected network interfaces
e2fsprogs - some general tools for creation of ext2 file systems etc.
hddtemp - Utility to monitor hard drive temperature
mtr-tiny - matt's traceroute great traceroute proggie
netcat - TCP/IP swiss army knife, quite helpful for network maintance tasks
snort - an Intrusion Detecting System
build-essential - installs basic stuff required for most applications compiled from source code
sysstat - generates statistics about server load each and every ten minutes, check man for more
lm-sensors - enables you to track your system hardware sensors information and warn in CPU heatups etc.

I believe the rest of them are no need to be explained, if you're not familiar with them check the manuals.
So far so good but this is not all I had to install, as you probably know most Apache webservers nowadays
are running PHP and are using a dozen of PHP libraries / extensions not originally bundled with PHP install
Therefore here are some more packages related to php to install that would install some more php goodies.

# install some packages required for many php enabled applications
debian-esrver:~# apt-get install php-http php-db php-mail php-net-smtp php-net-socket php-pear php-xml-parser
php5-curl php5-gd php5-imagick php5-mysql php5-odbc php5-recode php5-sybase php5-xmlrpc php5-dev

As I said that is mostly the basic stuff that is a must have on most of the Debian servers I have
configured this days, of course this is not applicable to all situations, however I hope
this would be of use to somebody out there.