DDBS: First (primary) disk needs rebuild.
DDBS: Second disk is valid for boot.
根据KB: Interpreting DDBS messages when a CLARiiON CX-Series array boots https://support.emc.com/kb/338122，解释如下：
|When a CX-Series array tries to boot, SP-A first looks for a good image on drive 0-0, its primary OS drive. When monitoring the boot process from HyperTerminal, you will see messages like the following when a serial cable is inserted into the SP:|
DDBS: MDDE (Rev 2) on disk 0
When the array fails to find a good image on drive 0-0, it fails the boot process. If you were to pull drive 0-0, the array will look to secondary drive 0-2 for a good image. If it finds a good image on that drive, it will boot up. In this example, the image on the secondary drive is valid for the array boots. If a valid image is not found on either drive, the boot-up fails and the drives must be re-imaged.
SP- A uses 0-0 and 0-2 as primary and secondary boot drives in that order.
SP-B uses 0-1 and 0-3 as primary and secondary boot drives in that order.
“蓝灯慢闪”是1/4 Hz频率的话，症状也符合KB: VNX How can we troubleshoot a faulted SP ? https://support.emc.com/kb/464621 中的描述：
|( 1 / 4 Hz Amber and/or Blue)||Invalid Master Boot Record (Corrupt Image)|
|Corrupted Data Directory Boot Service (DDBS)|
|SP is panicking and reboot count is getting cleared on every boot.|
|SP is panicking even after the reboot count trips.|
我也是怎么想的 ，之前碰到过类似问题，disabled spa write cache，然后单独启动spb，正常后插入spA，准备试试
Severity : Warning
System : FCN00114300207
Domain : Local
Created : Jan 5, 2017 6:37:42 PM
Message : Valid SP-Cache is for Storage Processor SP B.
Full Description : Valid SP-Cache is for Storage Processor SP B.
Recommended Action : Valid SP-Cache is for Storage Processor SP B.
Event Code : 0x7241