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MySQL database on Linux Tutorial

Create password root the first

# mysqladmin -u root password NEWPASSWORD

Change password user root

# mysqladmin -u root -p'oldpassword' password newpass

Create a MySQL Database

# mysql -u root -p

mysql> CREATE DATABASE myDB;

How To Create a New User and Grant Permissions in MySQL

mysql> CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'newuser'@'localhost';
mysql> FLUSH PRIVILEGES;

How To Grant Different User Permissions

• ALL PRIVILEGES- as we saw previously, this would allow a MySQL user all access to a designated database (or if no database is selected, across the system)
• CREATE- allows them to create new tables or databases
• DROP- allows them to them to delete tables or databases
• DELETE- allows them to delete rows from tables
• INSERT- allows them to insert rows into tables
• SELECT- allows them to use the Select command to read through databases
• UPDATE- allow them to update table rows
• GRANT OPTION- allows them to grant or remove other users' privileges

mysql> GRANT ALL PRIVILEGES  ON [database name].[table name] TO ‘[username]’@'localhost’; 

Note: All permission user for database name

mysql> GRANT [type of permission] UPDATE,INSERT ON [database name].[table name] TO ‘[username]’@'localhost’;

Backup and restore mysql database

# mysqldump -u root -p[root_password] [database_name] > dumpfilename.sql
# mysql -u root -p[root_password] [database_name] < dumpfilename.sql

For example

Backup

# mysqldump -u user01 -p123 mydb  > dumpfilename.sql

Restore

# mysql -u user01 -p123 mydb  < dumpfilename.sql

Query to determine the size of tables in a database

mysql> SELECT table_schema "Data Base Name", SUM( data_length + index_length) / 1024 / 1024 "Data Base Size in MB" FROM information_schema.TABLES GROUP BY table_schema;

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How to stop a background process in linux system

How to stop a background process in linux system? How many to stop a background process in linux system

For example running a background process:

# python server.py &

Method 1: use jobs command

[root@localhost project]# jobs
[1]+  Running                 python server.py &
[root@localhost project]# kill %1
[root@localhost project]# jobs
[1]+  Terminated              python server.py

Method 2: use ps command

[root@localhost project]# ps aux | grep server.py
root      1244  0.0  0.8  11068  4312 pts/0    S    16:47   0:00 python server.py
root      1246  0.0  0.1   4356   740 pts/0    S+   16:47   0:00 grep server.py
[root@localhost project]# kill -9 1244

Method 3: use fg to bring a background job back to foreground.

[root@localhost project]# jobs
[1]+  Running                 python server.py &
[root@localhost project]# fg 1
python server.py
^C

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ldap server configuration in centos 6 step by step

In this articles, how to install and configuration openldap in centos 6 step by step. openldap run 2 port: 389 ( insecure ) and 636 ( secure )

What does CN, OU, DC mean?

CN = infomon Name
OU = Organizational Unit
DC = Domain infoponent

Installing and configuration openldap server on in centos 6 

Step 1: Install LDAP

# yum install openldap*

Step 2: Now generate a encrypted password for Administrator User That is "Admin"

# slappasswd

NOTE: You need to copy above generated password to text

Step 3: Edit the following file:

# vi /etc/openldap/slapd.d/"cn=config"/"olcDatabase={2}bdb.ldif"

Change

olcSuffix: dc=linuxoperatingsystem,dc=info
olcRootDN: cn=Admin,dc=linuxoperatingsystem,dc=info
olcRootPW: <paste encrypted="" here="" password="" your=""> ( copy password at step 2 )
olcTLSCertificateFile: /etc/pki/tls/certs/linuxoperatingsystem.pem
olcTLSCertificateKeyFile: /etc/pki/tls/certs/linuxoperatingsystemkey.pem

Step 4: Now specify the Monitoring privileges

# vi /etc/openldap/slapd.d/"cn=config"/"olcDatabase={1}monitor.ldif"

Chage

"cn=manager,dc=linuxoperatingsystem,dc=info" 

 to

"cn=Admin,dc=linuxoperatingsystem,dc=info"

Step 5:  Now copy the sample database file

#cp /usr/share/openldap-servers/DB_CONFIG.example /var/lib/ldap/DB_CONFIG
#chown -R ldap:ldap /var/lib/ldap/

Step 6: Configure OpenLDAP to listen on SSL/TLS

# vi /etc/sysconfig/ldap
SLAPD_LDAPS=yes #(default is no)

Step 7: Now you need to create a certificate for OpenLDAP Server.

# openssl req -new -x509 -nodes -out /etc/pki/tls/certs/linuxoperatingsystem.pem -keyout /etc/pki/tls/certs/linuxoperatingsystemkey.pem -days 365

Step 8:You need to change owner and group ownership of certificate and keyfile

#chown -Rf root:ldap /etc/pki/tls/certs/linuxoperatingsystem.pem
#chown -Rf root:ldap /etc/pki/tls/certs/linuxoperatingsystemkey.pem

Step 9:  Start/Restart the service of OpenLDAP

# service slapd restart
# chkconfig slapd on

Step 10: Now you need to create base objects in OpenLDAP.

Create it manually or use migration tools to automation

I use tool to create .ldif file :

# yum install migrationtools
# cd /usr/share/migrationtools/
# ls
# vi migrate_common.ph

on the Line Number 61, change "ou=Groups"

  $NAMINGCONTEXT{'group'}             = "ou=Groups";

  on the Line Number 71, change your domain name

$DEFAULT_MAIL_DOMAIN = "linuxoperatingsystem.info";

on the line number 74, change your base name

$DEFAULT_BASE = "dc=linuxoperatingsystem,dc=info";

on the line number 90, change schema value

$EXTENDED_SCHEMA = 1;

For example: Creating 2 local users and groups and then I will migrate to LDAP

# useradd -d /home/ldapuser1 ldapuser1
# useradd -d /home/ldapuser2 ldapuser2

Now assign the password

# passwd ldapuser1
# passwd ldapuser2

Now you need to filter out these users from /etc/passwd to another file:

# getent passwd | tail -n 2 > /root/users

Now you need to filter out password information from /etc/shadow to another file:

# getent shadow | tail -n 2 > /root/passwords

Now you need to filter out user groups from /etc/group to another file:

# getent group | tail -n 2 > /root/groups

So Open the following file to change the location of password file

# vi migrate_passwd.pl

Inside this file search /etc/shadow and change it to /root/passwords and then save and exit.

Now generate a base.ldif file for your Domain, use the following:

#./migrate_base.pl > /root/base.ldif

Now generate a ldif file for users

# ./migrate_passwd.pl /root/users > /root/users.ldif

Now Generate a ldif file for groups

# ./migrate_group.pl /root/groups > /root/groups.ldif

Step 11: Now it' time to upload these ldif file to LDAP Server

# ldapadd -x -W -D "cn=Admin,dc=linuxoperatingsystem,dc=info" -f /root/base.ldif
# ldapadd -x -W -D "cn=Admin,dc=linuxoperatingsystem,dc=info" -f /root/users.ldif
# ldapadd -x -W -D "cn=Admin,dc=linuxoperatingsystem,dc=info" -f /root/groups.ldif

Enable log openldap Server

# vi /etc/rsyslog.conf

Add line following below into rsyslog.conf

# LDAP
local4.* /var/log/ldap.log

Restart Rsyslog server

# /etc/init.d/rsyslog restart

Restart openldap server

# /etc/init.d/slapd restart

Now you can use "ldapsearch" command

# ldapsearch -x -b "dc=linuxoperatingsystem,dc=info"

Test connect to Openldap server

I use JXplorer software as picture below :

Output:

Link youtube ldap server configuration in centos 6 step by step

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Centos grub boot missing

Redhat/Centos grub boot  missing. in order to boot from the Redhat/CentOS box with grub problems, you need to know 2 things:

• The /boot partition
• The root (/) partition.

Problem Redhat/centos grub boot missing not login into server.

Step 1: find the /boot partition/

List available disks at grub prompt

grub> find (hd        -->TAB key

List available disk partition at grub prompt

grub> find (hd0,        -->TAB key

Examples of find command a grub.conf file

grub> find (hd0,0)//grub/grub.conf
   (hd0,0)
   (hd0,1)
   (hd0,2)

grub> find (hd0,0)/boot/grub/grub.conf
   Error 15: File not found

Step 2: The root (/) partition.

grub> root (hd0,0)
grub> kernel /vmlinuz-2.6.32-431.el6.i686 ro root=/dev/sda1
grub> initrd /initramfs-2.6.32-431.el6.i686.img
grub> boot

For example my system:

# fdisk -l

# ls -la  /boot

Redhat/Centos grub boot  missing, the linux commands above helpful you! 

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How to install ibus-unikey ubuntu 14.10

Step by step install ibus-unikey on ubuntu 14.10. solve problem Error: "Can’t connect to iBus".

Step 1: The first install "m17n engine" in Ubuntu Software Center
Step 2: Open terminal or press ctr+alt+T, type commands as below:

$ sudo apt-get update
$ sudo apt-get install ibus-unikey
$ sudo reboot

Run ibus on ubuntu 14.10

$ ibus-daemon -d

Setup ibus on ubuntu 14.10

$ ibus-setup

Configuration ibus-unikey

when reboot lose ibus-unikey, then you startup application system as picture bellow:

Fix error ibus-unikey with skype, firefox,....

Install packages ibus-qt4

#sudo apt-get install ibus-qt4

 Add line following below /etc/X11/xinit/xinput.d/default file :

 

# /etc/X11/xinit/xinput.d/default 

#
XIM=ibus
XIM_PROGRAM=/usr/bin/ibus-daemon
XIM_ARGS="--xim"
XIM_PROGRAM_XTRA=
# Set following variable to non-zero string if program set itself as deamon
XIM_PROGRAM_SETS_ITSELF_AS_DAEMON=
#
# Define GTK and QT IM module
# They may or may not be using xim as the IM.
#
GTK_IM_MODULE=ibus
QT_IM_MODULE=ibus

#
# Define lists of packages neded for above IM to function
#
DEPENDS="ibus, ibus-gtk, ibus-gt4"

#
# Define X start up hook script to update IM environment
#

Reboot system

# reboot

Output:

Link youtube how to install ibus-unikey ubuntu 14.10

I hope will this help you

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ubuntu commands

ubuntu commands

Seach the cached list of packages the contain a command or description

$ apt-cache search nload

Search the list of installed packages

$ dpkg-query -S mount

List all the files contained in the initscripts package

$ dpkg -L initscripts

Refresh the list of cached packages

$ sudo apt-get update

• APT: Use APT to download and install packages form online repositories.
• dpkg: Use dpkg to work with .deb files
• aptitude: Use aptitude at the command line for working with online repositories

To report on the total number of packages available

$ apt-cache stats

Output:

Total package names: 60926 (1,219 k)
Total package structures: 102901 (5,762 k)
  Normal packages: 71359
  Pure virtual packages: 1187
  Single virtual packages: 9068
  Mixed virtual packages: 1825
  Missing: 19462
........

Enabling More Repositories for apt

$ sudo vim /etc/apt/sources.list

In a minimal system install, adding software collections with tasksel

$ sudo tasksel

Managing software with APT

check for updates to the packages

$ sudo apt-get update

To fid packages in any available repository

$ apt-cache search [package-name]

Install package

$ sudo apt-get install [package-name]

Display information about the software

$ apt-cache show [package-name]

Check updates for all installed packages and then prompt to download and install them with this command

$ sudo apt-get upgrade

Run this command anytime to delete partially downloaded packages, or packages no longer installed

$ sudo apt-get autoclean

Remove all cached packages from /var/cache/apt/archives to free up disk space using this command

$ sudo apt-get clean

This command removes the named package and all its confiuration fies

$ sudo apt-get --purge remove [package-name]

This command does a sanity check for broken packages. This tries to fix any

$ sudo apt-get -f install

This command lists GPG keys that APT knows about

$ sudo apt-key list

Check for dependencies the packages

$ sudo apt-cache depends [package-name]

Removing packages

$ sudo apt-get remove [package-name]

Clean up packages

$ find /var/cache/apt/ -name \*.deb
$ sudo apt-get clean

Downloading packages

$ sudo apt-get download [package-name]

Managing software with dpkg

This command lists all installed packages

$ dpkg -l

This command lists all the files that have been installed from a package

$ dpkg -L [package-name]

Install a package

$ sudo dpkg -i [package-name]

Remove a package

$ sudo dpkg -r [package-name]

Remove package and configuration file

$ sudo dpkg -P [package-name]

Verifying install packages with debsums

$ debsums -a Check all files, include config files left out by default
$ debsums –e Check config files for packages only
$ debsums –c List only changed files to stdout
$ debsums –l List files that don't have md5sum info
$ debsums –s List only errors; otherwise be silent
$ debsums package List the packages you want debsums to analyze

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