Posts in Category: SysAdmin

Proxy using SSH Tunnel

Browse the web using your SSH Server by making it a proxy server.

SSH

How to auto start services on boot in Centos / Redhat / Oracle Linux?

To auto start services in Centos, Redhat or Oracle Linux, you can use builtin chkconfig utility. It is located in /sbin directory. If you are a regular user (non-root), then /sbin may not be in your path. Therefore, you may have to use the full path to access the chkconfig utility.

To know the commands click “Continue reading”…


How to use different user and group for just one Virtual Host in Apache

apacheWith the mpm-itk that is a multi-processing module (MPM) you can run each virtualhost with it’s own user id and group id. This is basically used to make a shared hosting secured, since you don’t have to make all virtualhosts folders readeable by apache user.

mpm-itk is based on the traditional prefork MPM, which means it’s non-threaded; in short, this means you can run non-thread-aware code (like many PHP extensions) without problems.

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How to fix “Can’t locate Search/Xapian.pm in @INC”

perlError: Can't locate Search/Xapian.pm in @INC (you may need to install the Search::Xapian module) (@INC contains: /path/to/something /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at (eval 143) line 2. BEGIN failed--compilation aborted at (eval 143) line 2.

To fix this, in ubuntu 14.04, just type:

$ sudo apt-get install libsearch-xapian-perl

How to fix “Can’t locate Sort/Naturally.pm in @INC”

perlCan't locate Sort/Naturally.pm in @INC (you may need to install the Sort::Naturally module) (@INC contains: /path/to/something /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at (eval 145) line 2.
BEGIN failed--compilation aborted at (eval 145) line 2.

To fix this, in ubuntu 14.04, just type:

$ sudo apt-get install libsort-naturally-perl

How to disable apache logs

To diapachesable apache logs (access and error log) to avoid excessive writes on local server just open your /etc/apache2/apache2.conf file and change the following two configurations:
Change the ErrorLog to:
ErrorLog /dev/null
Now, open /etc/apache2/conf.d/other-vhosts-access-log and comment the following line
#CustomLog /var/log/apache2/other_vhosts_access.log vhost_combined
In addition, you might have to change these files:
/etc/apache2/sites-available/default-ssl
/etc/apache2/sites-available/default
and change the ErrorLog and comment out the CustomLog:
ErrorLog /dev/null
#CustomLog ${APACHE_LOG_DIR}/access.log combined

If you have more VirtualHosts, you need to make the same configuration for them.

Source; lleess

AWS lowers cloud pricing by launching the T2 instance type that can burst to handle occasional workload spike

awsT2 instances are Burstable Performance Instances that provide a baseline level of CPU performance with the ability to burst above the baseline. The baseline performance and ability to burst are governed by CPU Credits. Each T2 instance receives CPU Credits continuously at a set rate depending on the instance size.  T2 instances accrue CPU Credits when they are idle, and use CPU credits when they are active.  T2 instances are a good choice for workloads that don’t use the full CPU often or consistently, but occasionally need to burst (e.g. web servers, developer environments and small databases).

Click continue reading for more.


htop

htoplogohtop is an interactive text-mode system-monitor process viewer for GNU/Linux. It aims to be a better ‘top’. It shows a frequently updated list of the processes running on a computer, normally ordered by the amount of CPU usage. Unlike top, htop provides a full list of processes running, instead of the top resource-consuming processes. htop uses color and gives visual information about processor, swap and memory status.

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Simplify your life with SSH config file and ClusterSSH

SSHIf you’re anything like me, you probably log in and out of a half dozen remote servers on a daily basis. And if you’re even more like me, you have trouble remembering all of the various usernames, remote addresses and command line options for things like specifying a non-standard connection port or forwarding local ports to the remote machine. And sometimes you have to do the same thing in a lot of servers, this post is for you.

To simplify your life, press continue reading :-)


Apache restrict access based on IP address to selected directories

Apache restrict access based on IP address to selected directories

Apache web server allows server access based upon various conditions. For example you just want to restrict access to url http://subdomain.domain.com/ (mapped to /var/www/subdomain directory) from 192.168.1.0/24 network (within intranet).

Apache provides access control based on client hostname, IP address, or other characteristics of the client request using mod_access module.

Press continue reading to understand how to do this!