RAC CSS diagwait参数的作用和设置方法

diagwait 参数的作用延迟节点重启的时间值，以便RAC后台进程写出必要的诊断信息到各自的日志中。
Diagwait:

Delay the node reboot for a short time to write all diagnostic messages to the logs.

Doesn’t increase of probability of data corruption

Setup steps: shutdown CRS

crsctl set css diagwait 13 –force
restart CRS
Set diagwait to 13
Will set the oprocd margin to 10 seconds instead of 500ms
Will prevent unneccesary node evictions under high load
Is a general recommendation for servers under high load, not specific to Oracle VM

Please review Metalink note 559365.1 on how to set this

If diagwait > reboottime then OPROCD_DEFAULT_MARGIN := (diagwait – reboottime) * 1000

设置css diagwait的步骤：

1. crsctl stop crs
#<CRS_HOME>/bin/oprocd stop

<2>. Ensure that Clusterware stack is down on all nodes by executing
#ps -ef |egrep “crsd.bin|ocssd.bin|evmd.bin|oprocd”
This should return no processes. If there are clusterware processes running and you proceed to the next step, you will corrupt your OCR. Do
not continue until the clusterware processes are down on all the nodes of the cluster.

<3>. From one node of the cluster, change the value of the “diagwait” parameter to 13 seconds by issuing the command as root:
#crsctl set css diagwait 13 -force

<4>. Check if diagwait is set successfully by executing. the following command. The command should return 13. If diagwait is not set, the

following message will be returned “Configuration parameter diagwait is not defined”
#crsctl get css diagwait

<5>. Restart the Oracle Clusterware on all the nodes by executing:
#crsctl start crs

<6>. Validate that the node is running by executing:
#crsctl check crs

 
移除diagwait的设置

crsctl unset css diagwait