linux CentOS 6.5升级至CentOS 7完整步骤

查看当前的系统版本

[root@dev-middleware ~]# cat /etc/redhat-release 
CentOS release 6.5 (Final)
[root@dev-middleware ~]# uname -rm
2.6.32-431.el6.x86_64 x86_64

升级

添加1个yum的repo文件

vi /etc/yum.repos.d/upgrade.repo

[upg]
name=CentOS-$releasever - Upgrade Tool
baseurl=http://dev.centos.org/centos/6/upg/x86_64/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

安装升级工具

yum install redhat-upgrade-tool preupgrade-assistant-contents

执行预升级检查

# 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 would 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 : 01/11 ...finished (time 00:00s)
All changed files      : 02/11 ...finished (time 00:33s)
Changed config files   : 03/11 ...finished (time 00:00s)
All users              : 04/11 ...finished (time 00:00s)
All groups             : 05/11 ...finished (time 00:00s)
Service statuses       : 06/11 ...finished (time 00:00s)
All installed files    : 07/11 ...finished (time 00:01s)
All local files        : 08/11 ...finished (time 00:00s)
All executable files   : 09/11 ...finished (time 00:00s)
RedHat signed packages : 10/11 ...finished (time 00:00s)
CentOS signed packages : 11/11 ...finished (time 00:00s)
Assessment of the system, running checks / SCE scripts:
001/096 ...done    (Configuration Files to Review)
002/096 ...done    (File Lists for Manual Migration)
003/096 ...done    (Bacula Backup Software)
004/096 ...done    (MySQL configuration)
005/096 ...done    (Migration of the MySQL data stack)
006/096 ...done    (Changes related to moving from MySQL to MariaDB)
007/096 ...done    (PostgreSQL upgrade content)
008/096 ...done    (GNOME Desktop Environment underwent several design modifications in CentOS 7 rel                                                                   ease)
009/096 ...done    (KDE Desktop Environment underwent several design modifications in CentOS 7 relea                                                                   se)
010/096 ...done    (several graphic drivers not supported in CentOS 7)
011/096 ...done    (several input drivers not supported in CentOS 7)
012/096 ...done    (several kernel networking drivers not available in CentOS 7)
013/096 ...done    (several kernel storage drivers not available in CentOS 7)
014/096 ...done    (Names, Options and Output Format Changes in arptables)
015/096 ...done    (BIND9 running in a chroot environment check.)
016/096 ...done    (BIND9 configuration compatibility check)
017/096 ...done    (Move dhcpd/dhcprelay arguments from /etc/sysconfig/* to *.service files)
018/096 ...done    (DNSMASQ configuration compatibility check)
019/096 ...done    (Dovecot configuration compatibility check)
020/096 ...done    (Compatibility Between iptables and ip6tables)
021/096 ...done    (Net-SNMP check)
022/096 ...done    (Squid configuration compatibility check)
023/096 ...done    (Reusable Configuration Files)
024/096 ...done    (VCS repositories)
025/096 ...done    (Added and extended options for BIND9 configuration)
026/096 ...done    (Added options in DNSMASQ configuration)
027/096 ...done    (Packages not signed by CentOS)
028/096 ...done    (Obsoleted rpms)
029/096 ...done    (w3m not available in CentOS 7)
030/096 ...done    (report incompatibilities between CentOS 6 and 7 in qemu-guest-agent package)
031/096 ...done    (Removed options in coreutils binaries)
032/096 ...done    (Removed options in gawk binaries)
033/096 ...done    (Removed options in netstat binary)
034/096 ...done    (Removed options in quota tools)
035/096 ...done    (Removed rpms)
036/096 ...done    (Replaced rpms)
037/096 ...done    (GMP library incompatibilities)
038/096 ...done    (package downgrades)
039/096 ...done    (restore custom selinux configuration)
040/096 ...done    (General)
041/096 ...done    (samba shared directories selinux)
042/096 ...done    (CUPS Browsing/BrowsePoll configuration)
043/096 ...done    (CVS Package Split)
044/096 ...done    (FreeRADIUS Upgrade Verification)
045/096 ...done    (httpd configuration compatibility check)
046/096 ...done    (bind-dyndb-ldap)
047/096 ...done    (Identity Management Server compatibility check)
048/096 ...done    (IPA Server CA Verification)
049/096 ...done    (NTP configuration)
050/096 ...done    (Information on time-sync.target)
051/096 ...done    (OpenLDAP /etc/sysconfig and data compatibility)
052/096 ...done    (OpenSSH sshd_config migration content)
053/096 ...done    (OpenSSH sysconfig migration content)
054/096 ...done    (Configuration for quota_nld service)
055/096 ...done    (Disk quota netlink message daemon moved into quota-nld package)
056/096 ...done    (SSSD compatibility check)
057/096 ...done    (Luks encrypted partition)
058/096 ...done    (Clvmd and cmirrord daemon management.)
059/096 ...done    (State of LVM2 services.)
060/096 ...done    (device-mapper-multipath configuration compatibility check)
061/096 ...done    (Removal of scsi-target-utils)
062/096 ...done    (Configuration for warnquota tool)
063/096 ...done    (Disk quota tool warnquota moved into quota-warnquota package)
064/096 ...done    (Architecture Support)
065/096 ...done    (Binary rebuilds)
066/096 ...done    (Debuginfo packages)
067/096 ...done    (Cluster and High Availability)
068/096 ...done    (Quorum implementation)
069/096 ...done    (fix krb5kdc config file)
070/096 ...done    (File Systems, Partitions and Mounts Configuration Review)
071/096 ...done    (Read Only FHS directories)
072/096 ...done    (Sonamebumped libs)
073/096 ...done    (SonameKept Reusable Dynamic Libraries)
074/096 ...done    (Removed .so libs)
075/096 ...done    (In-place Upgrade Requirements for the /usr/ Directory)
076/096 ...done    (CA certificate bundles modified)
077/096 ...done    (Developer Tool Set packages)
078/096 ...done    (Hyper-V)
079/096 ...done    (Content for enabling and disabling services based on CentOS 6 system)
080/096 ...done    (Check for ethernet interface naming)
081/096 ...done    (User modification in /etc/rc.local and /etc/rc.d/rc.local)
082/096 ...done    (cgroups configuration compatibility check)
083/096 ...done    (Plugable authentication modules (PAM))
084/096 ...done    (Foreign Perl modules)
085/096 ...done    (Python 2.7.5)
086/096 ...done    (Ruby 2.0.0)
087/096 ...done    (SCL collections)
088/096 ...done    (System kickstart)
089/096 ...done    (YUM)
090/096 ...done    (Check for usage of dangerous range of UID/GIDs)
091/096 ...done    (Incorrect usage of reserved UID/GIDs)
092/096 ...done    (NIS ypbind config files back-up)
093/096 ...done    (NIS Makefile back-up)
094/096 ...done    (NIS server maps check)
095/096 ...done    (NIS server MAXUID and MAXGID limits check)
096/096 ...done    (NIS server config file back-up)
Assessment finished (time 01:12s)
Result table with checks and their results for main contents:
----------------------------------------------------------------------------------------------------                                                                   -----------
|Bacula Backup Software                                                                    |notappli                                                                   cable     |
|Migration of the MySQL data stack                                                         |notappli                                                                   cable     |
|Changes related to moving from MySQL to MariaDB                                           |notappli                                                                   cable     |
|PostgreSQL upgrade content                                                                |notappli                                                                   cable     |
|GNOME Desktop Environment underwent several design modifications in CentOS 7 release      |notappli