Category Archives: FAQs

SquirrelMail Time out issue

If you are using Squirrel mail and often encounter a disconnection problem with SquirrelMail interface, then you need understand that SquirrelMail session gets disconnected after a certain period of time. This usually happens around 10-15 minutes after logged into the interface without clicking on any buttons or not performing any actions.

For example,

You are composing a very long email or staying away from the computer for several minutes or a few hours then it attempts to log out from mail interface. read more

Domain pointing to external MX on Plesk

If you are using external MX record and also using Linux environment for your Plesk server, then you need tweak settings in Plesk panel. To change the settings follow the below guidelines:

1 – You need to update the DNS for your domain name.

1	1 – You need to update the DNS for your domain name.

a) Change or Add MX record to establish external email server with significant priorities.
b) Remove the “CNAME” for mail.yourdomain.com if not to be used for configuration 
c) Or Edit “CNAME” for your domain that will point to external email server (generally provided by the email service provider).
d) Or Add “A” record for mail.yourdomain.com to point to external email server.

a) Change or Add MX record to establish external email server with significant priorities.

b) Remove the “CNAME” for mail.yourdomain.com if not to be used for configuration

c) Or Edit “CNAME” for your domain that will point to external email server (generally provided by the email service provider).

d) Or Add “A” record for mail.yourdomain.com to point to external email server.

It will take some time to propagate the changes made in the DNS.

2 – Once the DNS is formed to use for external email server, it is essential
to de-activate the Mail service for the domain form the Plesk.

1 2	2 – Once the DNS is formed to use for external email server, it is essential to de-activate the Mail service for the domain form the Plesk.

- Login as Admin to your Plesk panel
- In Domains &gt; search your desired domain and go into that Domain
- Click on “Mail” (it has drop down options)
- Click on “Mail Settings” or other option is “Create Mailing List”
- Under Mail Preference you need to “uncheck” the option of “Activate mail service on domain”
- Click “OK” button to save the settings

- Login as Admin to your Plesk panel

- In Domains > search your desired domain and go into that Domain

- Click on “Mail” (it has drop down options)

- Click on “Mail Settings” or other option is “Create Mailing List”

- Under Mail Preference you need to “uncheck” the option of “Activate mail service on domain”

- Click “OK” button to save the settings

The above settings must eliminate the entry for the domain from the below two “qmail” server configuration files.

&gt;&gt; /var/qmail/control/rcpthosts
&gt;&gt; /var/qmail/control/virtualdomains

1 2	>> /var/qmail/control/rcpthosts >> /var/qmail/control/virtualdomains

After exclusion of above two entries, your Plesk server will search for the external email server for the domain by fetching MX records from its DNS. read more

How to optimize image online in Linux?

linux

Online image optimization in Linux:

Image compression may have an interest in many situations. For example, while writing a web article in which we need compressed images to reduce the total weight of a web page. Image compression may also need while sending an email. For this it is worthwhile to know how to do it quickly from command line. So here we will see how to lighten images in PNG, JPEG/JPG format with various tools.

PNG images optimization with pngcrush

First we need install pngcrush, in Debian we will use the below command:

apt-get install pngcrush

1	apt-get install pngcrush

For CentOS and RHEL, use this syntax:

yum install pngcrush

1	yum install pngcrush

Once installed, pngcrush is very easy to use, for example:

pngcrush -brute -e "compressedimage.png" image_original.png

1	pngcrush -brute -e "compressedimage.png" image_original.png

Here, “-brute” allows us better optimization of the image, “-e” compress the original image (Note: after specifying “-e” mention the name for compressed image which will be the output of the tool). read more

Linux process CPU usage monitoring

In this tutorial we will see how to collect CPU usage of a Linux process.

The main purpose behind this query is supervision or debugging. It would be convenient if you know how to retrieve CPU usage of a particular Linux process. It is often noticed people only check overall CPU usage on a machine, but don’t bother to analyze, which process is consuming more CPU time. Once they start focusing on which process consumes more CPU, then it will be helpful for them to optimize that process.

So in this tutorial we will see how to check usage of specific Linux process: read more

Explore the Debian packages with Apt-file

Debian package management Apt-file to explore the Debian packages: when one uses only the command line on Linux, there are tools to have in your pocket, so apt-file for exploring the Debian packages (.deb) and finds a package according to a file. Here, we are going to see how to use it:

First we will see the installation and preparation of apt-file: Apt-file is simply installed on Debian via deposits, it will capture the following command.

apt-get install apt-file

1	apt-get install apt-file

It will then prepare apt-file to be used in fulfilling its cache; this requires a simple command line that I’ve mentioned below: read more

How to know playback speed of a hard drive with Debian?

Debian

Today, we will see a trick to calculate the playback speed of a hard drive, Linux and specifically with Debian in this tutorial. For this, we will rely on fdisk to list the hard drives, and hdparm for the calculation of performance.

First, we are going to see procedure with hdparm so let’s start by listing the drives on the machine with the following command:

fdisk -l | grep "Disque"

1	fdisk -l \| grep "Disque"

Note: the presence of two discs: sda and sdb. About md0 and md1 it is software RAID arrays present on the machine. read more

How to create a Windows 8 VM quickly?

Use Convert-WindowsImage and create a Windows 8 VM quickly.

Written in PowerShell, Convert-WindowsImage is a tool to quickly create a Windows installation on a VHD virtual hard disk or VHDX, from a Windows installation ISO file.

This tool can be used from the command line or GUI, it’s your choice. No installation required since it’s a PowerShell script.

In terms of compatibility, it can be used in Windows 8, but is recommended for Windows 8.1 and Windows Server 2012 R2. Then you can work with the ISO Supported OS, specifically Windows 7 / Windows Server 2008 R2 and newer OS. read more

How to use ifconfig under CentOS 7?

As we all know that recently CentOS released a new version “7”, this new stable version has its own share of change and among them, the fact that the ifconfig control no longer present in the native system. So if you have old habits, then you may want to find this option in this newer version. And I am sure you probably not the only one trying to reinstall it on CentOS 7.

So the first question you may ask whether ifconfig is already available in the package?

To regain use of ifconfig and related network management commands, you should find the name of the package containing the command. The command yum gives and option to search a package according to the order that is sought rather handy. You need to use the option “provides” as below: read more

What is lsyncd?

Lsyncd combines the advantages of inotify with the functionality of Rsync. This means lsyncd holds a remote copy of a directory permanently to the state that corresponds to the local directory.

Technically lsyncd begins at the start with a full Rsync run, but sets simultaneously on all the monitored directories and subdirectories inotify watches. All changes to the data reports through Kernel to lsyncd. This collects these messages and then initiates at short intervals for the changed files and re-run Rsync. read more

10 questions about RAID Technology

Storage solutions, professionals, etc… always heavily loaded with RAID configuration. But do you know this technology. I guess, yes. However, today I am going to ask some basic questions about RAID; below each question you will see 3 options + correct answer. At first glance it will looks quite boring or rather uninteresting but did you know this information before, ask yourself.

Question 1/10 – What do the initials RAID?

Redundant Array of Independent Disks Redundant Association of Inexpensive Disks Asynchronous Data record of Informatics

The correct answer is – 1) Redundant Array of Independent Disks

Question 2/10 – What architecture does one opposes regularly RAID?
read more