Category Archives: Linux

Encrypt files

Here are some ways you can encrypt files on a linux system. GPG To encrypt a file with gpg, run You will be asked to enter password. Example boby@hon-pc-01:~$ gpg –symmetric –cipher-algo AES256 -o ~/work/MY_FILES/forums.txt boby@hon-pc-01:~$ To decrypt, run

Last logged in users

last is a command used to list last logged in users on a linux system. [root@m3722 ~]# last root pts/0 Wed Jul 19 21:55 still logged in root pts/0 Tue Jul 18 19:58 – 20:00 (00:01) root pts/0

Server Load – Disk I/O

Here are some commands to monitor and identify Disk I/O related server loads. iostat iostat give stats about disk i/o usage. Some of the important values are * %iowait = if this value is higher, your server is waiting on

Server Load

When your server is under load, you need to identify the bottleneck. This can be CPU, Memory or Disk IO. Here are some of the useful commands that help you identify cause of high server load. uptime uptime is the

AH01215: Can’t locate in @INC

On a web site using xpanel control panel (free hosting script created with perl), i get error This is because perl-CGI module was missing on the server. On CentOS 7 server, you can install it with command

Find SSL certificate details with OpenSSL

If you have .crt file, you can find more details about the certificate with command To get details of SSL installed on a web site, use csr


fail2ban-client can be used to interact with fail2ban jails. To see help, run To see status of jails, run To see status of a jail, run To view value of a setting, run To change a value in run time,

Installing MongoDB on Ubuntu

To install mongodb on Ubuntu, run To check version of mongodb installed, run root@backup:~# mongo –version MongoDB shell version: 2.6.10 root@backup:~# Install latest version from The mongodb provided by your operating system maybe older, to get latest stable version,

Ubuntu working to smooth Unity 7 to GNOME transition

Canonical, developer of popular Ubuntu linux distro will be replacing Unity Desktop Environment on Ubuntu with GNOME. They were working on Unity 8 and Mir display server, but decided to discontinue the development after they stop development of Mobile OS.

tee linux command

tee is a linux command that allows you to redirect out put of a command to STDOUT (console) and a file. This is helpful when you want to see result of a long running process, also want to save it