Difference between RHEL5 and RHEL6

Difference between RHEL5 and RHEL6

1.   Virtualization:

In RHEL6 new virtualization KVM (kernel Based Virtual Machine) was used as a hypervisor but in the earlier releases of RHEL XEN was used as a hypervisor.

The main advantage of KVM is that it supports the installation of many virtual machines/operating systems like Windows, Linux, Solaris and also it is very easy to manage those virtual machines. The new kernel should not be installed in KVM like in Xen.

2.   EXT4 File System:

Ext4 has many new advantages than Ext3 which is used in earlier versions of RHEL. Ext4 is comparatively faster and easy to manage. Currently, Ext3 support 16 TB of maximum file system size, and 2 TB of maximum file size. Ext4 adds 48-bit block addressing, so it will have 1 EB of maximum file system size and 16 TB of maximum file size

The expected benefit from using Ext4 over Ext3 would be a lower accounting overhead (fewer blocks on disk dedicated to file system metadata) and an increased throughput in sequential IO as extent based file systems tend to group data physically together, reducing internal fragmentation.

3.   Security:

RHEL6 has advanced level of security. SELinux (Security Enhanced Linux) features are improved and a new set of SELinux rules has been added to provide security to virtual machines from hackers and attackers. This new feature is called SVirt.

4.   Networking Features:

RHEL6 is released with improved and new networking features. It supports IPv6. It uses NFSv4 (Network File Transfer) for the sharing of files in the network rather than NFSv3. It also supports iSCSI (internet Small Computer System Interface) partitions. The network manager in RHEL6 supports Wi-Fi capabilities.