Cloud DevOps Admin Guide

Below are the major differences between RHEL 6 and 7.

Difference on the basis of operating system names
if we want to see use this command
# cat /etc/redhat-release
RHEL 6: SANTIGO
RHEL 7: MAIPO

Kernel version
If we want to see in terminal use this command: lsb_release -a or uname -a
RHEL 6: 2.6.32
RHEL 7: 3.0.10

OS boot time
RHEL 6: 40 sec
RHEL 7: 20 sec

Maximum size of single partition
RHEL 6: 50TB(EXT4)
RHEL 7: 500TB(XFS)

Boot loader
RHEL 6: /boot/grub/grub.conf
RHEL 7: /boot/grupb2/grub.cfg

Processor architecture
RHEL 6: It support 32bit & 64bit both
RHEL 7: It only support 64bit

How to format or assign a file system in
RHEL 6: # mkfs.ext4 /dev/hda6
RHEL 7: # mkfs.xfs /dev/hda6

How to repair a file system in
RHEL 6: # fsck -y /dev/hda6
RHEL 7: # xfs_repair /dev/hda6

Command to manage network
RHEL 6: # setup
RHEL 7: # nmtui

Host name configuration file
RHEL 6: /etc/sysconfig/network
RHEL 7: /etc/hostname

Default ISO image mount path
RHEL 6: /media
RHEL 7: /run/media/root

File system check
RHEL 6: e2fsck
RHEL 7: xfs_repair

Resize a filesystem
RHEL 6: # resize2fs -p /dev/vg00/lv1
RHEL 7: # xfs_growfs /dev/vg00/lv1

Tune a filesystem
RHEL 6: tune2fs
RHEL 7: xfs_admin

IP tables and firewalls
RHEL 6: iptables
RHEL 7: firewalled

Communication between TCP and UDP in backend
RHEL 6: netcat
RHEL 7: ncat

Interface name
RHEL 6: eth0
RHEL 7: ens198(N)

Combining NIC
RHEL 6: Network Bonding
RHEL 7: Team Driver

NFS server version
RHEL 6: NFSv2
RHEL 7: NFSV4

Database used
RHEL 6: Mysql
RHEL 7: mariaDB

Managing services
RHEL 6:
# service sshd restart
# chkconfig sshd on
RHEL 7:
# systemctl restart sshd
# systemctl enable shhd