Re: softIOC through network file system

[Jeong Han Lee <jhlee@ibs.re.kr>]

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.
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