Experimental Physics and
Industrial Control System

Hi,

I've been wondering: is there a standard (or common) way of loading IOC configuration data upon power up? If one have a site with, say, 100 computers (x86), each running an IOC, then what would be the best way to load their configuration? I'm thinking basically in two scenarios where this would be necessary:

1. During testing, when configuration (and/or binaries) might change often

2. Diskless systems, which don't have local storage and must load their data when they boot

Suppose there is a DHCP server which gives them their IP addresses. For the diskless systems, I think something like PXE to boot a Operating System would be necessary. 

Then, once booted, I thought about some solutions:

1. Mount remote folders residing in a server, via NFS. Maybe the name of the folder would contain the IP address of the interface, so you could have, for instance, a file tree in the server that would look like:

nfs/

  general/  --> for all IOC's (binaries, maybe)

  10.0.0.2/ --> for each IOC (st.cmd, .db files, etc)

  10.0.0.3/

  10.0.0.120/

Would this solution overload the network? This is the simplest solution, I think.

2. Use the same scheme above, but copy all the necessary data locally, then umount the NFS folder. In a system with local storage, this copy could happen conditionally, only if the local files differ from the remote ones. There would be a lot of shell scripts to be written.

3. Write scripts that run in the server and use scp to copy the files to the computers. The server would have to keep track of the versions of the files in the systems with disk to avoid unnecessary copies.

4. Use git. Since I'm already checking for different versions, why not go full version control? In this situation, there would be a "general" git repository and then one repository for each IP. Once booted, a computer would simply do a git pull (or a git clone if it is a diskless system) and then it would have all the latest files locally.

Of course, this is a naïve approach. So, before going into the trouble of implementing and testing these, I came here to see if any of you could point out a better way of doing this, or if you have advice about any of those four "solutions".

Thanks in advance!

Best regards,

Bruno Martins

-- 
Bruce Hill
Member Technical Staff
SLAC National Accelerator Lab
2575 Sand Hill Road M/S 10
Menlo Park, CA  94025