在RHCS服務切換的時候，unmount盤的時候，發現會failed，並且直接導致reboot。
在message里看到這樣一段
[lvm] * initrd image needs to be newer than lvm.conf
red hat對此的解釋是：
Bug 728365 - any change to lvm.conf results in an invalid HA configuration
For HA LVM to work properly, the initrd which the system uses during the boot process must be in-sync with lvm.conf.
A warning and an error are produced if the initrd is younger than lvm.conf.
This has been reduced to simply an error message due to possible issues it can cause once the HA setup is operating
原來是我們生成了initrd image 后又修改了lvm.conf文件，導致initrd image 舊，從而HA失敗
於是重新生成新的initrd image
dracut -H -f /boot/initramfs-$(uname -r).img $(uname -r)
再次測試的時候，沒有了上述信息，並且切換正常，不會導致reboot