The following will not work in a shared hosting environment. If you are using shared hosting, consider moving to a VPS. The cost is similiar and you get the full capabilities of a standalone Linux server.

The correct answer to website file permissions is chmod 600 for files and chmod 700 for directories. On a properly setup server, the http daemon runs under it’s own account. You only need to allow the http daemon read and write access to the website files and directories. You do not need the http daemon group having access nor do you need to allow any other user or process having access.

Why chmod 600 for files? For older sites written in CGI,Python, Ruby, Perl or system executables, you need execute permissions. For PHP and serving most modern webcontent such as html and javascript, there is no need to allow execute permissions.

Why code>chmod 700 for directories? You need to alloow the httpd daemon to enter directories.

There is a catch, chmod -R 700 /path/to/website will set everythign under /path/to/website to 700. chmod -R 600 /path/to/website will make your subdirectories inaccessible to the http daemon.

The trick is to set chmod 600 for files and chmod 700 for directories.

chmod -R ugo=,u+rwX /path/to/website


What this does is clear all permissions, then sets the user permission to rw and the capital X sets only the directories as executable("x").

This only covers 2 possible file types and the patterns would also have to checked with a better regex to not miss files.

Install heartbeat.
yum install heartbeat

Copy needed files:
cp /usr/share/doc/heartbeat-2.1.4/authkeys /etc/ha.d/
cp /usr/share/doc/heartbeat-2.1.4/ha.cf /etc/ha.d/
cp /usr/share/doc/heartbeat-2.1.4/haresources /etc/ha.d/

Edit authkeys:
vi /etc/ha.d/authkeys
auth 2
2 sha1 test-ha
Secure authkeys:
chmod 600 /etc/ha.d/authkeys

Edit HA confiure file:
vi /etc/ha.d/ha.cf

Add/change:
logfile /var/log/ha-log
logfacility local0
keepalive 2
deadtime 30
initdead 120
bcast eth0
udpport 694
auto_failback on
node node-1.mydomain.com
node node-2.mydomain.com

Edit haresources:
vi /etc/ha.d/haresources
Add
node-1.mydomain.com 10.100.100.101 httpd

Edit httpd.conf to listen on new IP:
vi /etc/httpd/conf/httpd.conf
Listen 10.100.100.101:80

On node 1:
echo "node-1.mydomain.com apache test server" > /var/www/html/index.html

On node 2:
echo "node-2.mydomain.com apache test server" > /var/www/html/index.html

Restart heartbeat:
/etc/init.d/heartbeat restart

User accounts
adduser is alias to useradd – add a new user account
useradd [options] LOGIN
useradd -m -g wheel -s /bin/bash newadminuser

passwd – modify user passwords
passwd [OPTION...] LOGIN
passwd newadminuser

groupadd – Add a new group
groupadd [options] group

usermod [options] LOGIN
usermod -G admins newadminuser

Shell customization
alias – create an alias
unalias – remove alias
alias [-p] [name[=value] … ]
alias rm=’rm -i’

Searching files and text

awk
find – Find files
find [path...] [expression]
find / -type f -iname “core”

grep – find text in files
grep [OPTION]… PATTERN [FILE] …
grep -r ’500′ /var/log/httpd/*

Networking

dig – dns lookups
dig [@global-server] [domain] [q-type] [q-class] {q-opt}
{global-d-opt} host [@local-server] {local-d-opt}
[ host [@local-server] {local-d-opt} [...]]
dig linuxpractive.com mx

losf – list of open files
[-?abhlnNoOPRstUvVX] [+|-c c] [+|-d s] [+D D] [+|-f]
[-F [f]] [-g [s]] [-i [i]] [+|-L [l]] [+m [m]] [+|-M] [-o [o]]
[-p s] [+|-r [t]] [-S [t]] [-T [t]] [-u s] [+|-w] [-x [fl]] [-Z [Z]] [--] [names]
lsof -Pnl +M -i4

Netstat
netstat –help
netstat [-veenNcCF] [] -r netstat {-V|–version|-h|–help}
netstat [-vnNcaeol] [ ...]
netstat { [-veenNac] -I[] | [-veenNac] -i | [-cnNe] -M | -s } [delay]
netstat -npl
netstat -l

nslookup – qery dns
nslookup [ - option ] … host [ server ]
nslookup server localhost host www.google.com
nslookup -type=mx google.com

File and directory commands

ls – List directory contents

ln – create links and shortcuts.
Usage: ln [OPTION]… [-T] TARGET LINK_NAME (1st form)
or: ln [OPTION]… TARGET (2nd form)
or: ln [OPTION]… TARGET… DIRECTORY (3rd form)
or: ln [OPTION]… -t DIRECTORY TARGET… (4th form)
ln /var/log/maillog maillog

link – create a link
link filename linkname
link /var/log/maillog maillog

unlink – Remove a link
unlink maillog

du – shoow disk usage

df – show free space

There are 7 init runlevels (RH based distros).

You can set the default run level by modifying the inidefault parameter in /etc/inittab.

vi /etc/inittab
Change the line:
id:3:initdefault:
And then Reboot.
init 6

Parse error: syntax error, unexpected $end in /path/to/wordpress/wp-content/plugins/wordpress-social-login/includes/plugin.settings/plugin.settings.1.php on line 167

Other areas of this plugin will show a similiar error.

On line 90 of plugin.settings.1.php change:
<?
To
<?php
On line 91 of plugin.settings.4.php change:
<?
To
<?php
On line 34, 61 and 88 of plugin.settings.7.php change:
<?
To
<?php

I recently encountered this problem again and have found a proper solution.

Open your wp-config.php file for editing and add:

define('FS_METHOD','direct');

To the end of the file. Save it and no more ftp prompt. You can also do this simply with:

echo "define('FS_METHOD','direct');" >> /path/to/wp-config

While you are logged into the server, might as well check and fix any insecure file permissions. Change [webowner] and [/path/to/website] to their respectivce values for yoru server.

chown -R webowner:webowner /path/to/website
find /path/to/website -type d | xargs chmod 700
find /path/to/website -type f | xargs chmod 600

And before you log out, might as well check your logs and make sure they are secured.

Install APC

pecl install apc

# NOTE: You may need to install a specific version of apc, the pecl message will alert you which to install.

Check your apc install

php -r 'phpinfo();' |grep apc

Setup APC

Get max shared memory “shmmax.” This will give a return a number, eg.. 68

cat /proc/sys/kernel/shmmax

Edit apc.ini in /etc/php.d/apc.ini. this example uses a shared memory size of 3x shmmax.

; Enable apc extension module
extension=apc.so
apc.shm_size=204M
;apc.shm_segments=3

NOTE: If apc was compiled with mmap (Meopry Mapping) support, then you do not need to specify the ;apc.shm_segments parameter. Make the apc.shm size a multiple of shmmax and make sure you append the G or M to end end to indicate size.

Restart Apache  

/etc/init.d/httpd graceful

Find apc.php and copy it to a website on your server, edit the password parameters at the beginning of the file. Visit the website you intend to use APC on and browse around it to get as many pages as possible cached. Then return to the apc.php page and see how much memory is beng used and how severe the fragmentation is. If fragmentation is high, increate shm_size incrementally until you can visit all website pages with little to no fragmentation.

For more information on the Alternative PHP Cache (APC)
to http://php.net/manual/en/book.apc.php