sl 6.1升级以后，版本为什么不变？centos不知道是不是同样问题？

引用:

[root@FileServer gogo11]# clear
[root@FileServer gogo11]# yum clean all
Loaded plugins: security
Cleaning repos: sl sl-security
Cleaning up Everything
[root@FileServer gogo11]# yum update
Loaded plugins: security
sl | 2.5 kB 00:00
sl/primary_db | 3.4 MB 00:04
sl-security | 1.9 kB 00:00
sl-security/primary_db | 9.9 MB 00:10
Setting up Update Process
No Packages marked for Update
[root@FileServer gogo11]# cat /etc/issue
Scientific Linux release 6.1 (Carbon)
Kernel \r on an \m

[root@FileServer gogo11]# lsb_release -a
LSB Version: :core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: Scientific
Description: Scientific Linux release 6.1 (Carbon)
Release: 6.1
Codename: Carbon