为更换版本或开发新业务新功能,EWSD交换机需执行PATCH。出于安全考虑,在执行PATCH时,通常保护一侧硬盘,即对一侧硬盘 维护闭塞,关掉电源。EWSD交换机采用双备份硬盘,硬盘上存放着系统文件、计费文件、局数据、告警和历史文件等重要内容。如果在执行PATCH期间,由于外部原因(如掉电)或操作员误操作使另一侧硬盘掉到UNA状态,即造成DOUBLE DISK FAILURE时,应怎样处理才能保住硬 EWSD switches need to execute PATCH to change versions or develop new capabilities for new services. For security reasons, during the implementation of PATCH, usually one side of the hard drive protection, maintenance of one side of the hard drive is blocked, turn off the power. EWSD switches use dual backup hard disks, which contain important contents such as system files, accounting files, office data, alarms and history files. If during the execution of PATCH, the hard disk on the other side should fall into the UNA state due to external reasons (such as power loss) or operator misoperation, that is, when the DOUBLE DISK FAILURE is caused, what should be done to keep the hard