Enable the query cache in MySQL to improve performance

If you want to get optimized and speedy response from your MySQL server then you need to add following two configurations directive to your MySQL server:

query_cache_size=SIZE
The amount of memory (SIZE) allocated for caching query results. The default value is 0, which disables the query cache.

query_cache_type=OPTION
Set the query cache type. Possible options are as follows:
0 : Don’t cache results in or retrieve results from the query cache.
1 : Cache all query results except for those that begin with SELECT S_NO_CACHE.
2 : Cache results only for queries that begin with SELECT SQL_CACHE

Howto enable caching in MySQL

You can setup caching as follows:
$ mysql -u root –p
Output:

Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 16 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Now setup cache size 16Mb:

mysql> SET GLOBAL query_cache_size = 16777216;

Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'query_cache_size';

Output:

 +------------------+----------+
| Variable_name    | Value    |
+------------------+----------+
| query_cache_size | 16777216 |
+------------------+----------+

You can setup them in /etc/my.cnf (Red Hat) or /etc/mysql/my.cnf (Debian) file:
# vi /etc/my.cnf
Append config directives as follows:

query_cache_size = 268435456
query_cache_type=1
query_cache_limit=1048576

In above example the maximum size of individual query results that can be cached set to 1048576 using query_cache_limit system variable. Memory size in Kb.


Parallels Plesk Panel Typical Installation with One-Click Installer

Use the One-Click Installer utility to perform a clean installation of Panel in one step. The utility automatically determines your operating system and installs the latest version of an appropriate distribution package in the typical configuration. One-Click Installer works only on Linux operating systems.

To install Panel, run one of the following commands on behalf of the root user.

If you have the wget utility, run
wget -O - http://autoinstall.plesk.com/one-click-installer | sh
If you have the curl utility, run
curl http://autoinstall.plesk.com/one-click-installer | sh
If you have the fetch utility, run
fetch -o - http://autoinstall.plesk.com/one-click-installer | sh

Plesk Website


How to check the version of PHP ?

To verify the update is working create a simple testphp.php in your www directory with the following source code:

and open it in a web browser. The new PHP version should be reflected at the top of the page.

Or

ssh into the server or run the follwing command in terminal

php -v


How can I downgrade my version of PHP ?

Iphp 5.3 on Fedora 17 or Redhat using atomic repo.

You will need to remove php and httpd first (not compulsory)

yum remove php
yum remove httpd

Add the following at the end of /etc/yum.conf(if required)

exclude=php*5.4*

Install php from atomic repo

wget -q -O - http://www.atomicorp.com/installers/atomic | sh
yum install php

More details at 
http://www6.atomicorp.com/channels/atomic/fedora/17/x86_64/RPMS/

How do I restart Parallels Plesk Panel

This can be done using the following commands when logged in as root via SSH on the Parallels Plesk Panel (PP) server:

Parallels Plesk Panel for Linux:

~# /etc/init.d/psa stop
~# /etc/init.d/psa start

Parallels Plesk Panel installed on FreeBSD server in versions prior to 8.1:

~# /usr/local/psa/rc.d/psa stop
~# /usr/local/psa/rc.d/psa start

Parallels Plesk Panel on FreeBSD since version 8.1:

~# /usr/local/etc/rc.d/psa.sh stop
~# /usr/local/etc/rc.d/psa.sh start


How to correctly uninstall DrWeb antivirus

Uninstall DrWeb from my Parallels Plesk Panel server because we do not use it.

nswer

Log in to the server under root and do the following:

Remove DrWeb antivirus packages:

# rpm -e drweb-updater drweb-common drweb-bases drweb-base drweb-daemon psa-drweb-configurator

Go to Server > Server Components (or Tools & Settings > Server Components on Plesk 10.x and newer) and update list of server components to detect that Dr.Web has been removed.

After that, run forced update of mail server configuration:

# /usr/local/psa/admin/sbin/mchk --without-spam

Remove the cron entry remaining after the uninstallation:

# rm -rf /var/spool/cron/drweb
# rm -rf /etc/cron.daily/drweb-update

Discontinue monitoring of the service by Watchdog:

/usr/local/psa/admin/bin/modules/watchdog/wd --unmonit-service=drweb