具体安装过程如下：
[root@localhost Server]# yum install sysstat-7.0.2-12.el5.x86_64.rpm
Loaded plugins: product-id, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Examining sysstat-7.0.2-12.el5.x86_64.rpm: sysstat-7.0.2-12.el5.x86_64
Marking sysstat-7.0.2-12.el5.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package sysstat.x86_64 0:7.0.2-12.el5 set to be updated
--> Finished Dependency Resolution
Dependencies Resolved
===============================================================================================================================================================================================
Package Arch Version Repository Size
===============================================================================================================================================================================================
Installing:
sysstat x86_64 7.0.2-12.el5 /sysstat-7.0.2-12.el5.x86_64 418 k
Transaction Summary
===============================================================================================================================================================================================
Install 1 Package(s)
Upgrade 0 Package(s)
Total size: 418 k
Is this ok [y/N]: y
Downloading Packages:
warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID 37017186
Public key for sysstat-7.0.2-12.el5.x86_64.rpm is not installed
这是由于yum安装了旧版本的GPG keys造成的，解决办法是可以运行下面命令进程注册：
rpm --import /etc/pki/rpm-gpg/RPM*