Good insights, Barry. I didn't consider the possibility of long running database users. Surely if they're still connected the database will likely not want to shutdown. Unless there's a shutdown option to ignore connected users unless they're actually active (I'm not that familiar with Oracle, so I can't say).
I expect that there may be other applications where SIGNAL SHUTDOWN actually causes more damage than it's intended to, so YMMV. Perhaps it will be a matter of testing your own virtual machines and paying attention to any exceptions that come up, particularly the databases. Thanks. van Sleeuwen, Berry wrote:
Hello Rich, Indeed, if the application has the correct init scripts and the SIGNAL is trapped to a "shutdown -h now" then a SIGNAL would correctly shutdown the application and the guest. But only if the SIGNAL has been given enough time to shutdown before CP will force the user. That would trigger my question, how to determine what the correct time would be? We started with 300 seconds, and two years ago we increased the time to 600 secs. But we have discovered that even 5 minutes could well be too short to shutdown the database. I have noticed that there is no way to be able to tell what the shutdowntime would be, for several reasons. The most obvious would be the number of guests that have to be shutdown and the CPU and PAGE load that this process would trigger. More users means more time is required to shutdown all machines. But a second problem could be when the database is not shutting down. We have seen active connections preventing the database to shutdown. In that case the database will not shutdown in time, therefore the linux guest will not shutdown in time. Some time ago I discussed this with IBM and they told me that while SIGNAL can shutdown systems (VM, Linux, VSE, SFS etc) it is not intended to guarrantee a clean shutdown of services within the machine. So we changed our instruction to not use SIGNAL and do a manual shutdown. This includes an application engineer to shutdown the application, a database admin to shutdown the database and the linux admin to shutdown the guest. We still want to try to automate the process but as long as SIGNAL will force the user if it takes too long we will not include a SIGNAL SHUTDOWN for a guest. Regards, Berry.
-- Rich Smrcina VM Assist, Inc. Phone: 414-491-6001 Ans Service: 360-715-2467 rich.smrcina at vmassist.com http://www.linkedin.com/in/richsmrcina Catch the WAVV! http://www.wavv.org WAVV 2009 - Orlando, FL - May 15-19, 2009 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
