Experimental Physics and
Industrial Control System

From: Hu, Yong <yhu at bnl.gov>
Sent: Wednesday, July 21, 2021 6:39 PM
To: Johnson, Andrew N. <anj at anl.gov>; Feister, Scott <scott.feister at csuci.edu>
Cc: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Re: Best practices for booting IOC at Linux startup?

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Johnson, Andrew N. via Tech-talk <tech-talk at aps.anl.gov>
Date: Wednesday, July 21, 2021 at 7:23 PM
To: Feister, Scott <scott.feister at csuci.edu>
Cc: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Re: Best practices for booting IOC at Linux startup?

In case it wasn’t obvious: Starting IOCs inside tmux or procServ (or GNU Screen as we use at APS) is recommended to allow you to connect to the IOC console and run diagnostic commands using the IOC shell, in case you need to debug issues with the IOC or its client connections. It is possible to create and run IOCs without a shell, but it provides many commands which can give you information about what it’s doing which you can’t otherwise access remotely.

The procServ package is probably the simplest approach, but it doesn’t give you the ability to scroll back and look at messages that were shown on the IOC console before you connected, like tmux or Screen can. You can have procServ log the console output to a file though, or if you start it using systemd it could send everything to the systemd journal.

Recent versions of procServ come with support scripts for use with systemd; post here if you have questions about them.

HTH,

- Andrew