用packstack安装了Openstack的Havana版本，想安装最新的icehouse版本试试，但是不知道怎么卸载或者删除之前安装的Openstack，那么多的组件和服务怎么才能卸载干净呢？找了官方文档才发现，原来已经提供了卸载RDO的方法，需要运行一个脚本就能解决问题。官方声称未来会支持从版本N升级到版本N+1。
如果是在虚拟机中安装的Openstack，强烈建议对虚拟机做快照，这样如果有地方出了问题，方便回到出问题之前的状态。

Big hammer method

运行下面的脚本可以完全卸载RDO，包括所有的程序数据，组件包等。注意：这里假设你在这台机器上面只跑了Openstack！如果这台机器还有其他用途，那么请使用Slightly smaller hammer method这个方法。

# Warning! Dangerous step! Destroys VMs
for x in $(virsh list --all | grep instance- | awk '{print $2}') ; do
virsh destroy $x ;
virsh undefine $x ;
done ;
# Warning! Dangerous step! Removes lots of packages, including many
# which may be unrelated to RDO.
yum remove -y nrpe "*nagios*" puppet ntp ntp-perl ntpdate "*openstack*" \
"*nova*" "*keystone*" "*glance*" "*cinder*" "*swift*" \
mysql mysql-server httpd "*memcache*" scsi-target-utils \
iscsi-initiator-utils perl-DBI perl-DBD-MySQL ;

ps -ef | grep -i repli | grep swift | awk '{print $2}' | xargs kill ;

# Warning! Dangerous step! Deletes local application data
rm -rf /etc/nagios /etc/yum.repos.d/packstack_* /root/.my.cnf \
/var/lib/mysql/ /var/lib/glance /var/lib/nova /etc/nova /etc/swift \
/srv/node/device*/* /var/lib/cinder/ /etc/rsync.d/frag* \
/var/cache/swift /var/log/keystone ;

umount /srv/node/device* ;
killall -9 dnsmasq tgtd httpd ;
setenforce 1 ;
vgremove -f cinder-volumes ;
losetup -a | sed -e 's/:.*//g' | xargs losetup -d ;
find /etc/pki/tls -name "ssl_ps*" | xargs rm -rf ;
for x in $(df | grep "/lib/" | sed -e 's/.* //g') ; do
umount $x ;
done

Slightly smaller hammer method

下面的脚本只删除特定的程序数据和组件包，会留下一些Openstack相关的数据。

for x in $(virsh list --all | grep instance- | awk '{print $2}') ; do
virsh destroy $x ;
virsh undefine $x ;
done ;
yum remove -y "*openstack*" "*nova*" "*keystone*" "*glance*" "*cinder*" "*swift*" "*rdo-release*";

# Optional - makes database cleanup cleaner.
# If you do this bit, the database cleanup stuff below is superfluous.
# yum remove -y "*mysql*"

ps -ef | grep -i repli | grep swift | awk '{print $2}' | xargs kill ;

rm -rf /etc/yum.repos.d/packstack_* /var/lib/glance /var/lib/nova /etc/nova /etc/swift \
/srv/node/device*/* /var/lib/cinder/ /etc/rsync.d/frag* \
/var/cache/swift /var/log/keystone /tmp/keystone-signing-nova ;

# Ensure there is a root user and that we know the password
service mysql stop
cat > /tmp/set_mysql_root_pwd << EOF
UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
FLUSH PRIVILEGES;
EOF

# mysql cleanup
/usr/bin/mysqld_safe --init-file=/tmp/set_mysql_root_pwd &
rm /tmp/set_mysql_root_pwd
mysql -uroot -pMyNewPass -e "drop database nova; drop database cinder; drop database keystone; drop database glance;"

umount /srv/node/device* ;
vgremove -f cinder-volumes ;
losetup -a | sed -e 's/:.*//g' | xargs losetup -d ;
find /etc/pki/tls -name "ssl_ps*" | xargs rm -rf ;
for x in $(df | grep "/lib/" | sed -e 's/.* //g') ; do
umount $x ;
done

还可以，使用单条命令

for x in $(virsh list --all | grep instance- | awk '{print $2}') ; do virsh destroy $x ; virsh undefine $x ; done ; yum remove -y nrpe "*nagios*" puppet ntp "ntp-*" ntpdate "rdo-release" "*openstack*" "*nova*" "*keystone*" "*glance*" "*cinder*" "*swift*" mysql mysql-server httpd "*memcache*" scsi-target-utils iscsi-initiator-utils perl-DBI perl-DBD-MySQL ; ps -ef | grep -i repli | grep swift | awk '{print $2}' | xargs kill ; rm -rf /etc/nagios /etc/yum.repos.d/packstack_* /root/.my.cnf /var/lib/mysql/ /var/lib/glance /var/lib/nova /etc/nova /etc/swift /srv/node/device*/* /var/lib/cinder/ /etc/rsync.d/frag* /var/cache/swift /var/log/keystone /tmp/keystone-signing-nova ; find /etc | grep rpmsave | xargs rm -vf ; umount /srv/node/device* ; killall -9 dnsmasq tgtd httpd ; setenforce 1 ; vgremove -f cinder-volumes ; losetup -a | sed -e 's/:.*//g' | xargs losetup -d ; find /etc/pki/tls -name "ssl_ps*" | xargs rm -rf ; for x in $(df | grep "/lib/" | sed -e 's/.* //g') ; do umount $x ; done

根据需求不同，把上面适合使用的脚本写到一个脚本文件里面，然后使用chmod +x scripts.sh赋予执行权限，然后执行一下就可以了！