Of course, you will want to save each database separately in case you just want to restore one at a time plus it will be easier when restoring.

Here’s a script you can use, replace password with your root password.

#!/bin/bash
# webserverhacks.com

USER="root"
PASSWORD="password"
OUTPUTDIR="."
MYSQLDUMP="/usr/bin/mysqldump"
MYSQL="/usr/bin/mysql"

# clean up any old backups - save space
rm "$OUTPUTDIR/*sql" > /dev/null 2>&1

# get a list of databases
databases=`$MYSQL -u$USER -p$PASSWORD -e "SHOW DATABASES;" | tr -d "|
" | grep -v Database`

# dump each database in turn
for db in $databases; do
   echo $db
   $MYSQLDUMP --force --opt -u$USER -p$PASSWORD $db > "$OUTPUTDIR/$db.sql"
done

Go into the directory zoneinfo:

cd /usr/share/zoneinfo

Then find the right zone file for you such as for me Los Angeles is for PST (Pacific Standard Time), which is here:

/usr/share/zoneinfo/America/Los_Angeles

Then simply copy over that file to /etc/localtime like this:

cp /usr/share/zoneinfo/America/Los_Angeles /etc/localtime

Run the date command:

date

and you should get something like:

Wed Jul 6 16:56:47 PDT 2011

Instead of the other time zone you were getting.

This can easily be changed via phpMyAdmin.

ssh-keygen -t dsa

Then do:

cat /root/.ssh/id_dsa.pub

Then copy over the whole thing into /root/.ssh/authorized_keys on the server you are trying to get connection.

This can be useful for setting up RSync between two servers.

To reset, get into SSH via console on your VPS web server company’s control panel.

Type:

service network stop

then

service network start

For some web servers, you might have to use:

/sbin/service network stop

and

/sbin/service network start

Wait like 5 seconds and see if you can ping the outside world:

ping google.com

If you get connected, you should be good to go.

This can save lots of time restarting a faulty network yourself instead of opening a support ticket and waiting forever.

I am still experimenting with PHP-FPM but it seems like a pretty good way to go as far as handling the PHP-CGI processes.

To do this, you will need to install EPEL & CentALT repositories:

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-3.noarch.rpm

rpm -Uvh http://centos.alt.ru/repository/centos/5/x86_64/centalt-release-5-3.noarch.rpm

Then do:

yum install php-fpm

to install php-fpm.

Edit the file /etc/php-fpm.conf

and my suggested setting changes:

<value name=”user”>apache</value>
<value name=”group”>apache</value>

The max_children is set to 1 as default, set it to something like 50, this really is the cool part about php-fpm.

<value name=”max_children”>50</value>

PHP-FPM doesn’t allow for root user and group so I set it to apache.  You will also need to set your web directories to apache user and group by doing:

chown apache:apache /mywebdirectory

Start the PHP-FPM by doing:

/sbin/service php-fpm start

If you get some kind of session errors, simply erase all the session files where the error shows.

For CentOS, you can do:

chkconfig php-fpm on

so it will start whenever your webserver is rebooted.

If you have been using fastcgi, make sure to do:

chkconfig fastcgi off

so it doesn’t interfere.

I’ve been researching many ways to optimize large file downloads but probably the best way is to simply rate limit the bandwidth on how fast each user can download.

You can add the following line to your HTTP directive in /etc/nginx/nginx.conf:

limit_rate 100k

This will limit each user to download at maximum of 100kb/second.

You can change this number to see which one fits best for your server.

You can also add limit_rate_after clause to only limit after a portion of the file has been downloaded:

limit_rate_after 1m;
limit_rate 100k

This will limit downloads only after the first megabyte, potentially not slowing down smaller file downloads and your website.

# mysql -version
mysql Ver 14.12 Distrib 5.0.45, for redhat-linux-gnu (i386) using readline 5.0

and for PHP version:

# php -version
PHP 5.2.6 (cli) (built: May 8 2008 08:53:44)

Most linux commands allow you to check the version simply by adding -version after the command.

WordPress by default hides error messages so this will reveal them.