Create mysql user with password :

# mysql

# create user wpuser identified by ‘wppass’;

Note : wpuser is the mysql username and follow by wppass is the mysql user password.

Grant privileges to mysql db :

# grant all privileges on wordpress.* to ‘wpuser’@'localhost’ identified by ‘wppass’;

Check privileges :

show grants for ‘wpuser’@'localhost’;
+————————————————————————————–+
| Grants for wpuser@localhost                                                          |
+————————————————————————————–+
| GRANT USAGE ON *.* TO ‘wpuser’@'localhost’ IDENTIFIED BY PASSWORD ‘7171e928058581f3′ |
| GRANT ALL PRIVILEGES ON `wordpress`.* TO ‘wpuser’@'localhost’                        |
+————————————————————————————–+
2 rows in set (0.01 sec)

The error faced when compiling PHP module to Apache2.

Sorry, I cannot run apxs.  Possible reasons follow:

1. Perl is not installed
2. apxs was not found. Try to pass the path using –with-apxs2=/path/to/apxs
3. Apache was not built using –enable-so (the apxs usage page is displayed)

The output of /usr/local/apache/bin/apxs follows:
./configure: /usr/local/apache/bin/apxs: /replace/with/path/to/perl/interpreter: bad interpreter: No such file or directory
configure: error: Aborting

Replace first line of /usr/local/apache/bin/apxs from,

#!/replace/with/path/to/perl/interpreter

with

#!/usr/bin/perl -w

Learn some chkconfig command today. This command is used to maintain the /etc/rc[0-6].d directory hierarchy.

First of all, lets understand and differentiate some of the /etc/rc[0-6].d .

rc1.d >>> Single user mode

rc2.d >>> Custom user mode

rc3.d >>>Multiple user mode with networking availability

rc4.d >>> Custom user mode

rc5.d >>> Multiple user mode with networking availability that has GUI mode (xlogin)

# chkconfig –list
haldaemon       0:off   1:off   2:off   3:on    4:on    5:on    6:off
httpd           0:off   1:off   2:off   3:on    4:off   5:off   6:off
ip6tables       0:off   1:off   2:on    3:on    4:on    5:on    6:off
iptables        0:off   1:off   2:on    3:on    4:on    5:on    6:off
kudzu           0:off   1:off   2:off   3:on    4:on    5:on    6:off
lvm2-monitor    0:off   1:on    2:on    3:on    4:on    5:on    6:off
mcstrans        0:off   1:off   2:on    3:on    4:on    5:on    6:off
messagebus      0:off   1:off   2:off   3:on    4:on    5:on    6:off
multipathd      0:off   1:off   2:off   3:off   4:off   5:off   6:off
mysqld          0:off   1:off   2:off   3:off    4:off   5:off   6:off
netconsole      0:off   1:off   2:off   3:off   4:off   5:off   6:off
netfs           0:off   1:off   2:off   3:on    4:on    5:on    6:off
netplugd        0:off   1:off   2:off   3:off   4:off   5:off   6:off
network         0:off   1:off   2:on    3:on    4:on    5:on    6:off
rdisc           0:off   1:off   2:off   3:off   4:off   5:off   6:off
restorecond     0:off   1:off   2:on    3:on    4:on    5:on    6:off
sshd            0:off   1:off   2:on    3:on    4:on    5:on    6:off
syslog          0:off   1:off   2:on    3:on    4:on    5:on    6:off

Now, mysqld service was set to off for rc3.d . We are going to On it in rc3.d level with below command.

# chkconfig –levels 3 mysqld on

Will see S64mysqld in /etc/rc3.d in my case. I see K36mysqld when levels 3 was off in my case.

Before install pureftp, I am going to show how to manually create a linux user, linux group and assign the user to grou[.

Add user:

# useradd ftpuser

Check user:

# less /etc/passwd

ftpuser:x:500:500::/home/ftpuser:/bin/bash

Add group:

# groupadd ftpgroup

Check group:

# less /etc/group

ftpgroup:x:500:

Assign user to group:

# vi /etc/group

change ftpgroup:x:500: to ftpgroup:x:500:ftpuser

Install pureftp:

1. Download pureftp installation file from ftp://ftp.pureftpd.org/pub/pure-ftpd/releases/ .
2. Extract the installation file at any directory.
3. Run ./configure –with-everything –with-paranoidmsg –without-capabilities -with-virtualchroot
4. Run make & make install
5. Done

Copy pureftp configuration to /etc :

# cp pure-ftpd-1.0.21/configuration-file/pure-ftpd.conf /etc

Copy pureftp startup script to /usr/local/sbin/ :

# cp pure-ftpd-1.0.21/configuration-file/pure-config.pl /usr/local/sbin/

Create a ftp user :

# pure-pw useradd test -u ftpuser -d /home/directoryname

• useradd > option of pure-pw
• test > the ftp username
• -u > linux username
• ftpuser > the linux user that created
• -d > path to the upload directory
• /home/directoryname > path name

Show ftp user detail :

# pure-pw show test

Output :

Login              : test
Password           : $1$h8ZLTun0$iYCeCgrYfMz0BrbLC/6Ca1
UID                : 500 (ftpuser)
GID                : 500 (ftpgroup)
Directory          : /home/directory/./
Full name          :
Download bandwidth : 0 Kb (unlimited)
Upload   bandwidth : 0 Kb (unlimited)
Max files          : 0 (unlimited)
Max size           : 0 Mb (unlimited)
Ratio              : 0:0 (unlimited:unlimited)
Allowed local  IPs :
Denied  local  IPs :
Allowed client IPs :
Denied  client IPs :
Time restrictions  : 0000-0000 (unlimited)
Max sim sessions   : 0 (unlimited)

Check ftp user option :

# pure-pw usermod test -h

Ftp user option normally stored in /etc/pureftpd.passwd . You will something like below when open this file.

test:$1$vrb6.MK0$/shIogHo4RVvQXr8bJSBe/:500:500::/home/directory/::::::::::::

Generate ftp database :

# pure-pw mkdb

The ftp database file will be created at /etc and named pureftpd.pdb .

Un-comment PureDB & AltLog varialble that store in /etc/pure-ftpd.conf .

Now, we can start the ftp service

# /usr/local/sbin/pure-config.pl /etc/pure-ftpd.conf

Done !!! Pureftp is installed. May try to connect to the ftp service via ftp client or ftp command.

Met this problem when I was compiling PHP5 for my testing virtual centos. Gotto temporary disable it by executing command,

/usr/sbin/setenforce 0

The problem happened when I could not start the Apache service when the production server was overloading.

root@servername [~]# service httpd start

(98)Address already in use: make_sock: could not bind to address 0.0.0.0:80

no listening sockets available, shutting down

Unable to open logs

Lets run the netstat to check the Apache process is hook up with which other process.

root@servername [~]# netstat -lnp | grep ‘0.0.0.0:80′

tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      22666/exim

Next, run the ps command to check above listening process

root@servername [~]# ps 22666

PID TTY      STAT   TIME COMMAND

22666 ?        S<s    0:00 /usr/sbin/exim -Mc 1L5ryZ-0005tZ-T0

GotYa. Is confirmed that Apache process could not stop due to Exim process.

Run the service reboot command to Exim service. Give a shoot by restarting Exim and then start Apache will wake up your Apache service.

Note : This is an example situation which it does not really relates to Exim process. It could be other process. Do check with netstat command and you will find out.