Linux tr command (translate)


The tr command is used to translate text. Example

You can also use

To change specific chars

To delete char, use -d option

See Linux Commands […]

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WordPress HyperDB


HyperDB is a WordPress plugin that allows you to use multiple MySQL database servers with large MySQL installations. It is used to to distribute MySQL server load amount multiple MYSQL database servers hosted in different data centers. HyperDB supports Read and write servers (replication) Configurable priority for reading and writing Local and remote datacenters […]

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Redirect Subdomain to Subdirectory

To redirect a subdomain to a subdirectory, use following .htaccess code.

Redirect Subdirectory to Subdomain

See htaccess […]

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Magento catalog_product_relation MySQL Error

On transferring a Magento website Database running on MySQL 5.7.34 to MariaDB 10.2.39, I get the following error

SQL Strict mode was already off on this MySQL server.

To fix the problem, edited the db.sql file, added

at the top of the file. After this change, the restore worked without any error. […]

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How to find Zimbra version

How to find Zimbra mail server version

To find the Zimbra version, log in to the server using SSH, then run the following commands. Switch to user “zimbra”

Run command zmcontrol -v, which will display the version of Zimbra you are using.


Using Zimbra Admin Login to Zimbra Admin area at

On Dashboard, you will see the […]

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MySQL Cluster

MariaDB Replication MariaDB galera cluster […]

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Skype public key is not available

I have Ubuntu 20.04 computer with skype installed. When I update software using apt update, I get an error

To fix this error, delete the key

Add the key again with

Now you can update software with

See Skype […]

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Flush exim mail queue

To flush mail queue, run command

Force another queue run

Force another queue run and attempt to flush the frozen message

See exim […]

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How to connect to lxd container

Linux Container

lxd is an easy-to-use command-line interface for lxc (Linux container). In this blog post, I will show how to create an lxd container and connect to it. To create an lxd container, run

Here vm-1 is the name of the container. ubuntu:20.04 tells lxc to create a new container with Ubuntu version 20.04. To […]

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lxc error Unable to fetch GPG key from keyserver

Linux Container

When i create an lxc container on the Ubuntu server, I get an error

To fix this, you can run

To make it permanent, add it to .bashrc

At the end of the file, add

Method 2 You can specify DOWNLOAD_KEYSERVER environment variable for the command with

Method 3 Use […]

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