Hello Folks.
I installed CentOS 6.X x64 on my HP server but after upgrade it to CentOS 7, It can't boot .
I used below link to upgrade it :

http://linuxsysconfig.com/2014/07/upgrade-to-centos-7/

Excuse me for silly question, It is logical to use CentOS 7 now? It is released recently and I ant to know am I on a right Track?

There is and NEVER has been a way to " upgrade" between MAJOR versions

it had NEVER been supported


you do a NEW clean fresh install on a newly reformatted partitions or drives

so
reformat to ext4
( or btfs )
and do a NEW install using cent7

most of the cent6 config files in the 6 home folder will NOT move over
some of the settings might
so MANUALLY move over settings at needed

Oh. Thus I can't Upgrade it . Excuse me, I set some ACL in Files and Directories and I want to know after the New install I should reconfig them?

to migrate to 7.0 from 6.6

first see the changelog and release notes

cent is using the redhat docs
(but IS NOT using proprietary redhat code )
https://access.redhat.com/documentat...Release_Notes/
http://wiki.centos.org/Manuals/ReleaseNotes/CentOS7

then on the testing mirrored server
test the new OS to make 100% sure OTHER programs work with the new OS

for one MySQL has been REPLACED with MariaDB
systemd replaced with systemV
the int scripts will NOT work

then after the mirrored server is working
swap out the 6.6 version with 7.0

-- this is not a minor version "upgrade"
but a full replacing of ALL the software with new and different versions

-- it will take some time

In your opinion, The best way is "Update" and not "Upgrade", OK?

http://wiki.centos.org/Manuals/Relea...51ac75669c68d3 says: See also http://wiki.centos.org/TipsAndTricks/CentOSUpgradeTool

Note the following is a given:
- you need to create a complete system backup before upgrading (don't ask just do),
- if you use any unofficial repositories you may expect problems,
- if your CentOS 6.6 is not completely current before running the preupgrade process you may expect problems,
- if you use third party vendor packages you may expect problems.


So simply put the best safest way is proceed is to install a clean version of CentOS-7.

Thank you for best reply and it was my problem. I upgraded CentOS 6.6 to 7 without reading release note and my system oopsed . I did a fresh install and everything is OK.