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Difference between RHEL7 and RHEL6









Diff. RHEL6 & RHEL7
RHEL4
5
6
7
FILE system
ext2
ext3
ext4
xfs
Kernel code
Nahant
tikanga
Santiago
maipo
Nw support
ipv4
ipv4
ipv4 and v6
ipv4 and v6
Yum server
no yum
yes
yes
yes
Max supp File size
2tb
16tb
EXT4 16TB with XFS 100TB
EXT4 16TB with XFS 500TB
Lang support
10
15
19
22
Virtualization
N/A
XEN Kernel
KVM (Kernel BasedVirtualization)
KVM included with Hyper-v Module
Boot Time


40 Sec
20 Sec
Default Database


MySQL
MariaDB
Processor Architecture


32Bit and 64Bit
Only 64Bit.
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 999Because Services are increased compare to RHEL 6
Boot Loader


Grub 0.97
/boot/grub/grub.conf
Grub 2
/boot/grub2/grub.conf
System Logs


/var/log/
rsyslog
/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 7. Run levels are called as targets
runlevel0.target -> Poweroff.target
runlevel0.target -> rescue.target
runlevel0.target -> multi-user.target
runlevel0.target -> multi-user.target
runlevel0.target -> multi-user.target
runlevel0.target -> graphical.target
runlevel0.target -> reboot.target
Poweroff  & Rebooting


poweroff – init 0
reboot – init 6
systemctl poweroff
systemctl reboot
Port Security


Iptables by default service port is enabled when service is switched on.
 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.
Network Interface Grouping


Bonding can be done as Active-Backup, XOR, IEEE and Load Balancing 
Team Driver will support multiple types of Teaming methods called Active-Backup, Load-balancing and Broadcast
Daemon & First  Process ID


Initd  Process ID 1
 Systemd Process ID 1
KDUMP


Kdump does’t support with large RAM Size 
RHEL 7 can be supported up to 3TB
max memory



x86


16gb
na
x86_64


12tb[64tb]^15
12tb[64tb]^16
Required minimum


x86


512mb minimum /1gb per loical cpu recommended
na
x86_64


1gb minimum /1gb per loical cpu recommended
1gb minimum /1gb per loical cpu recommended
minimum diskspace


1gb minimum /5gb  recommended
10gb minimum /20gb  recommended
File systems & Storage limits






XFS max file sys size


300TB[16EB]^19
500TB[16EB]
XFS max file size


100TB[8EB]
500TB[8EB]
XFS max subdirectories


unlimited
unlimited
EXT4 max file sys size


16TB[1EB]
50TB[1EB]
EXT4 max file size


16TB
16TB
max subdirectories


65000/unlimited
65000/unlimited
EXT3 max file sys size


16TB
16TB
EXT3 max file size


2TB
2TB
max subdirectories


32000
32000








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