Category Archives: Linux

Extend Volume Group and Logical Volume on CentOS/RHEL

Scenario: Added new disk /dev/sdc then extend Volume Group and extend Logical Volume /var on CentOS/RHEL
System: CentOS/RHEL 6/7 (ext4 filesystem)

Steps:
– After added disk /dev/sdc then create partition on /dev/sdc
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Setup Autologout on CentOS/RHEL

Scenario: How to setup autologout console and ssh session on CentOS/RHEL
System: CentOS/RHEL 6/7

By default on CentOS/RHEL fresh install system didn’t come with automatically logout, you must manually configure Linux system to automatically log users out after a period of inactivity.

Steps to set up system wide auto logout console and ssh session
1) Log in as root.
2) Create a new script file (to auto logout after 15 minutes),example we create autologout.sh.
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Install Ansible Core on CentOS 7

System: CentOS 7, Ansible-2.6.0

Step 1 — Installing Ansible
To begin exploring Ansible as a means of managing our various servers, we need to install the Ansible software on at least one machine.

To get Ansible for CentOS 7, first ensure that the CentOS 7 EPEL repository is installed:
# yum install epel-release

Install Ansible
# yum install ansible
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Create Partition on New Disk using Parted on CentOS


Scenario: Create partition and Volume Group 60GB size from 100GB disk on new disk using Parted on CentOS
System: CentOS/RHEL 6 or 7

Steps:
Show new disk:
# fdisk -l | grep sd

[root@server ~]# fdisk -l | grep sd
Disk /dev/sda: 64.4 GB, 64424509440 bytes, 125829120 sectors
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 81797119 39848960 8e Linux LVM
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
[root@server ~]#

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Mount Windows Folder Sharing on RHEL 6/CentOS 6

Scenario:
-Mount Windows Folder Sharing (CIFS) on RHEL 6/CentOS 6.
-Set only Linux user >> user1 that have RWX access.
-Hide sharing credentials from other Linux users.
-Mount permanent at boot.

System: CentOS 6

Steps:
1) Edit /etc/fstab
# vi /etc/fstab
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Setup Virtual Domain Postfix

Scenario:
– Forward certain email recipient to another email address.
– Forward local Unix account email address to another email recipient because in the Postfix server don’t have mailbox.

System:
Postfix on CentOS 7/RHEL 7 (also work on CentOS 6/RHEL 6)

Steps:
– Edit main.cf
# vi /etc/postfix/main.cf
Edit the below parameter.

virtual_alias_domains = example1.com,example2.com
virtual_alias_maps = hash:/etc/postfix/virtual

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Configure Display Date and Time in Bash History Command on CentOS/RHEL

Scenario: How to display date and time in bash history command on CentOS/RHEL.

By default default history command output didn’t show date and time.

[bachem@centos7ht ~]$ history
 1 sudo su
 2 su -
 3 sudo su
 4 su -
 5 ulimit -a

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Setup Ethernet Bonding on RHEL 6

Scenario: Configure 4 ethernet into 2 ethernet bond0 and bond1 on RHEL 6/CentOS 6.
System: RHEL 6.9

Steps:
1) Create new file bond0 (Eth0+Eth1) with IP Address = 172.16.10.70
# vi /etc/sysconfig/network-scripts/ifcfg-bond0

DEVICE=bond0
IPADDR=172.16.10.70
NETMASK=255.255.255.0
TYPE=Bond
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
USERCTL=no
PEERDNS=yes
IPV6INIT=no

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Clone CentOS 6/RHEL 6 VM template using Clonezilla

Scenario:
Clone RHEL 6 VM template to NFS server using Clonezilla for deploy to physical server.

System included:
– Clonezilla iso.
– RHEL 6 VM Template.
– Windows server 2012 R2 NFS server.
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