Upgrade CentOS 6.5 to CentOS 7.

Upgrade CentOS 6.5 to CentOS 7.

RedHat provides a redhat-upgrade-tool upgrade tool;
[1] Configuring software sources

# Vim/etc/yum. repos. d/upgrade. repo
[Upgrade]
Name = upgrade
Base url = http://dev.CentOS.org/centos/6/upg/x86_64/
Enable = 1
Gpgcheck = 0

[2] installing software tools
Yum-y install preupgrade-assistant-contents redhat-upgrade-tool preupgrade-assistant

[3] Check potential problems before Upgrade
# Preupg
Preupg tool doesn' t do the actual upgrade.
Please ensure you have backed up your system and/or data in the event of a failed upgrade
That wowould require a full re-install of the system from installation media. Do you want to continue? Y/n
Y
Gathering logs used by preupgrade assistant:
All installed packages: 01/10... finished (time 00: 00 s)
All changed files: 02/10... finished (time 00: 40 s)
Changed config files: 03/10... finished (time 00: 00 s)
All users: 04/10... finished (time 00: 00 s)
All groups: 05/10... finished (time 00: 00 s)
Service statuses: 06/10... finished (time 00: 00 s)
All installed files: 07/10... finished (time 00: 01 s)
All local files: 08/10... finished (time 00: 03 s)
All executable files: 09/10... finished (time 00: 00 s)
RedHat signed packages: 10/10... finished (time 00: 00 s)
Assessment of the system, running checks/SCE scripts:
001/100 .. done (Configuration Files to Review)
002/100 .. done (File Lists for Manual Migration)
003/100 .. done (Bacula Backup Software)
004/100 .. done (MySQL configuration)
005/100... done (Migration of the MySQL data stack)
006/100 .. done (General changes in default MySQL implementation)
007/100 .. done (PostgreSQL upgrade content)
Assessment finished (time 00: 00 s)
Result table with checks and their results for main contents:
Bytes ------------------------------------------------------------------------------------------
| System kickstart | notapplicable |
| YUM | notapplicable |
| Check for usage of dangerous range of UID/GIDs | notapplicable |
| Incorrect usage of reserved UID/GIDs | notapplicable |
| NIS ypbind config files back-up | notapplicable |
| NIS Makefile back-up | notapplicable |
| NIS server maps check | notapplicable |
| NIS server MAXUID and MAXGID limits check | notapplicable |
| NIS server config file back-up | notapplicable |
Bytes ------------------------------------------------------------------------------------------
Tarball with results is stored here/root/preupgrade-results/preupg_results-140716022514.tar.gz.
The latest assessment is stored in directory/root/preupgrade.
Upload results to UI by command:
E.g. preupg-u http: // 127.0.0.1: 8099/submit/-r/root/preupgrade-results/preupg_results-* .tar.gz.

[4] Start upgrading
# Rpm -- import http://centos.excellmedia.net/7.0.1406/ OS /x86_64/RPM-GPG-KEY-CentOS-7

The preceding commands can be upgraded normally;
# Redhat-upgrade-tool -- network 7.0 -- instrepo http://centos.excellmedia.net/7.0.1406/ OS /x86_64/

This force seems unfriendly, and the production environment should be used with caution;
Update to this step:
Setting up repos...
. Treeinfo | 1.1 kB
Getting boot images...
Vmlinuz-redhat-upgrade-tool | 4.7 MB 0:38
Initramfs-redhat-upgrade-tool.img | 32 MB 14: 45
Setting up update...
Finding updates 100% [======================================== ========================================================== ===============================]
(1/272): acl-2.2.51-12.el7.x86_64.rpm | 81 kB
(2/272): attr-2.4.46-12.el7.x86_64.rpm | 66 kB
(3/272): audit-2.3.3-4.el7.x86_64.rpm | 223 kB
(4/272): audit-libs-2.3.3-4.el7.x86_64.rpm | 77 kB
(5/272): authconfig-6.2.8-8.el7.x86_64.rpm | 399 kB
(6/272): basesystem-10.0-7.el7.centos.noarch.rpm | 5.0 kB
(7/272): bash-4.2.45-5.el7.x86_64.rpm | 1.0 MB
(270/272): yum-plugin-fastestmirror-1.1.31-24.el7.noarch.rpm | 28 kB
(271/272): zlib-1.2.7-13.el7.x86_64.rpm | 89 kB
(272/272): zlib-devel-1.2.7-13.el7.x86_64.rpm | 49 kB

Setting up system for upgrade
Finished. Reboot to start upgrade.

# Reboot

[5] upgrade completed:
# Cat/etc/redhat-release
CentOS Linux release 7.0.1406 (Core)