To calculate downtime of a SAS Server

[raj231]

Hi, 

I want to calculate the downtime of a SAS Server and have used last reboot command. The result was as given below:

reboot   system boot  3.2.17           Fri May 18 04:05 - 21:05 (17:00)
reboot   system boot  3.2.17           Fri May 18 03:05 - 21:05 (18:00)

Can someone suggest as how to calculate the down time between two successive reboots on the same day?

[Kurt_Bremser]

I guess that the earlier line is the result of a system crash, power outage or other hard reset where the shutdown was not recorded properly. In normal operations, you should have a shutdown time before 4:05 (the next boot).

If the server in question is set to automatic reboot in case of a crash, you might measure the time a reboot takes in such a case, so you can set a default downtime.

It's best to measure server uptimes from outside, eg by pinging regularly and recording failed pings. Even better by checking services that need to be up.