Experimental Physics and
Industrial Control System

Jeong Han Lee <[email protected]> · Thu, 20 Mar 2014 21:00:05 +0900

Hi Ralph,

 Thank you for your suggestion. We all use the same Debian

distributions except MOXA serial servers. And I maintains them (below

10 servers and PCs) regularly via clusterssh. So not much pain which I

have right now.

 Actually, it is the temporary solution I expect we may use this kind

of system until this year. However, I keep in mind your suggestion not

to use Network file system. Better to move as soon as possible to Debian

repository as you suggested.

  Thanks,
  Han

On 03/20/2014 08:43 PM, Ralph Lange wrote:

Hello Han,

I would not recommend this setup.

While putting executables and libraries on an NFS share is easy and Just
Works [tm] when you set it up, it will create painful difficulties later
on.
To work reliably, *all* client machines need to be on (more or less) the
same version of the same Linux distribution. Any crucial change in the
system libraries of a client, and everything on that client might stop
working immediately (the easy case) or just become instable and
sometimes crash for no obvious reasons (the painful case).
In such a setup, updating your machines to a new Linux version becomes
basically an all-or-nothing operation, requiring a huge time slot for
testing and verification. Also, your development machine will always
have to be on the oldest version around, to generate code that is
compatible with all your client machines.

Using an NFS share is fine for all non-binary data (EPICS IOC databases,
startup scripts, autoSaveRestore data, logs, ...), but I would always
recommend keeping binaries and libraries locally on your production
machines. The easiest and safest way is to use your system's style of
binary packages, but rsync'ing from your development machine is
basically fine, too - in that case you are responsible for tracking the
dependencies.

If you put the installation in the same place on all machines, that
could be the path that you compile into the softIOC.
Note, though, that this softIOC binary in base is intended for
development use. Most of your real-life soft IOCs will need driver code
(asyn, stream, ...) and come as binaries that are created in an IOC
application, and then deployed on your production systems.

Cheers,
~Ralph

--
Jeong Han Lee, Dr.rer.nat.
----------------------------
Accelerator Systems Division
Rare Isotope Science Project
Institute for Basic Science
Daejeon, South Korea
----------------------------
tel  : +82-42-878-8733
fax  : +82-42-878-8799

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System