How to Grant a New User to Root Privileges on CentOS 6 / CentOS 7

One recommended way to manage virtual private server (VPS) or a dedicated linux server is not using the root account as the main access for SSH login. This is because usually the hackers will try to brute force your root password and potentially get access to your server. Instead of using the default root account, […]

Ldapsearch Examples for 389 Directory


This post will show you the list of ldapsearch examples for 389 Directory. This ldapsearch examples assumes the following: a)This ldapsearch is search for uid in the directory. b)The 389 directory is configured to not support anonymous access, then the user “Directory Manager” and the password is required c)This ldapsearch command has been run on […]

How to Change Timezone Linux on RHEL 6/7 and CentOS 6/7

This post assumed that we will change the System Timezone from the command line without using redhat-config-date. There are several files and directories that are used for time zones. In RHEL 6 and RHEL 6, there is one directory that very useful to select the appropriate time zone which is /usr/share/zoneinfo directory. Sometimes we forget […]

Why “portmap unrecognized service” on RHEL 6/CentOS 6

Question : During the deployment of Samba and NFS services on one of the RHEL 6 server, I’m hit by this message when trying to start, stop and restart service portmap : [root@rhel6 ~]# service portmap start portmap: unrecognized service   Answer : Portmap is replaced by rpcbind on some linux distributions such as Fedora […]

How to Add User to root Group on CentOS 5/CentOS 6

useradd is a low-level utility to create new users to the system. When used without the -D option, useradd command will create a new user account using the command line plus the default values ??of the system. Depending on the command line option, useradd command will update system files and also can create new user’s […]