描述。  向节点发送 GSN_BACKUP_REQ 信号，导致该节点启动备份。

示例输出。 

Node 2: Backup 1 started from node 2
Node 2: Backup 1 started from node 2 completed
StartGCP: 158515 StopGCP: 158518
#Records: 2061 #LogRecords: 0
Data: 35664 bytes Log: 0 bytes

其他信息。  [N/A]