Thursday, 19 January 2017

A Major Difference Between RHEL 6 vs RHEL 7 Here you go

RHEL 7 vs RHEL 6

Red Hat Enterprise Linux 7 is an Light weight and minimized Operating system. RHEL 7 changes are huge effect to enterprise.

Let's see what changed in RHEL 7 as per administration prospective.

  • First one is Anaconda Installer Completely new.
  • Grub version updated from 0.97 to Grub 2 fast booting
  • Procedure of bypassing root password at booting process completely different than RHEL 6/5 
  • There is no SysV Initd in RHEL 7 it's an new Systemd
  • Run Levels are changed to Targets.
  • Default file system in RHEL 7 is XFS. XFS file system supports 550TB of each partition size in 64-bit.
  • Directories /bin /sbin /lib and /lib64 are moved under /usr/
  • Network Interface Names are changed from eth0 to ens.xxx
  • New concept to create multiple profiles top of one Ethernet card, No need of changing IP addresses and settings every time when you connect different networks, simply activate different profile.
  • GNOME version changed from 2 to 3
  • No classic registration system, completely changed to Red Hat subscription Manager
  • Default database is MariaDB instead of MySQL
  • Cluster Manager has been changed to Pacemaker and Corosync
  • Ifconfig command is deprecated, replaced with ip command
  •  User Identification Numbers (UID's) changed from 500 to 1000, which means when you create new normal user in RHEL 7 will get UID from 1000 to 65534
  • locate command is changed to mlocate
  •  yum commands are changed little bit

 
Feature Name RHEL 6  RHEL 7
Default File System Ext4 XFS
Kernel Version 2.6.xx 3.10.xx
Release Name Santiago Maipo
Gnome Version GNOME 2 GNOME 3.8
KDE Version 4.6 4.1
Release Date 10-Nov-10 10-Jun-14
NFS Version NFS 4 NFS 4.1. NFS V2 is deprecated in RHEL 7
Samba Version 3.6 4.4
Default Database MariaDB MySQL
Cluster Resource Manager Rgmanager Pacemaker
Network Grouping Team Driver will support multiple types of Teaming methods called Active-Backup, Load-balancing and Broadcase Bonding can be done as Active-Backup, XOR, IEEE and Loac Balancing
KDUMP RHEL 7 can be supported up to 3TB Kdump does't support with large RAM Size
Boot Loader Grub 2
/boot/grub2/grub.cfg
Grub 0.97
 /boot/grub/grub.conf
File System Check xfs_replair
- Inode blockmap checks
-Inode allocation map checks
-Inode size check
-Directory check
-Path Name check
-Link count check
-Freemap check
-Super block check
e2fsck
-Inode check. Block and size check
--Directory Structure check
-Directory Link Check
-reference count check
-Group Summary Check
Process ID Systemd (1) Initd (1)
Port Security Firewalld instead of iptables. Iptables can also support with RHEL 7, but we can't use both of them at the same time. Firewall will not allow any port until and unless you enabled it. iptables by default service port is enabled when service is switched on.
Boot Time 40 Sec 20 Sec
File System Size EXT4 16TB with XFS 100TB XFS 500TB with EXT4 16TB
Processor Architecture 32Bit and 64Bit Only 64Bit.
Network Configuration Tool steup nmtui
Hostname Config File /etc/sysconfig/network /etc/hostname No need to edit hostname file to write permanent hostname simply use hostnamectl command
Interface Name eth0 ens33xxx
Managing Services service sshd start
service sshd restart
chkconfig sshd on
systemctl start sshd.service
systemctl restart sshd.service
systemctl enable sshd.service
System Logs /var/log/ /var/log
journalctl
Run Levels runlevel 0 - Power Off
runlevel 1 - Single User Mode
runlevel 2 - Multi User without Networking
runlevel 3 - Multi User CLI
runlevel 4 - Not USed
runlevel 5 - GUI Mode
runlevel 6 - Restart
There is no run levels in RHEL 6. Run levels are called as targets
Poweroff.target
rescue.target
multi-user.target
graphical.target
reboot.target
UID Information Normal User UID will start from 500 to 65534
System Users UID will start from 1 to 499
Normal User UID start from 1000 - 65534
System Users UID will start from 1 to 999

Because Services are increased compare to RHEL 6
By Pass Root Password Prompt append 1 or s or init=/bin/bash to Kernel command line Append rd.break or init=/bin/bash to kernel command line
Rebooting and Poweroff poweroff - init 0
reboot - init 6
systemctl poweroff
systemctl reboot
YUM Commands yum groupinstall
yum groupinfo
yum group install
yum group info

Thanks, please provide your valuable feedback on the same.
 

1 comment:

  1. You have switched values in columns on some rows, ex. from "Boot Loader" to "Boot Time" and in few others

    ReplyDelete