Experimental Physics and
Industrial Control System

Adding my response to your earlier questions.

We have been using RHEL-7 (7.6 or later most recently I believe) to serve small RTEMS 4.9.2 and 4.10.2 systems (uC5282 boards so 68K with only 16MB RAM) over NFSv2, with no ill effects. I don’t think we’ve tested RHEL-8 as an NFSv2 server yet but we will have to fairly soon I’m sure. The ability to enable v2 is not a bug AFAIK, but Red Hat won’t actively support it.

I did read the other day that the latest Linux kernel release will not support NFS over UDP by default (v2 only works over UDP, I’m not sure about v3) so the writing is on the wall, but it’ll hopefully be a year or two until RHEL gets to that kernel.

I can’t promise, but I suspect APS would be willing to contribute towards the development of an NFSv3 (over TCP) client for RTEMS 4.x and the old network stack.



Hi Heinz and everyone,

Thanks for the replies and sharing your experiences.

We're also using the shared PowerPC (MVMExxxx), beatnik and MVME3100 bsp's. I believe these are all on the old network stack.

Is there a way to stay on RTEMS 4.10.x and implement these two major steps: 

1) Upgrade to the new libbsd stack (does it require RTEMS 5?).

2) Upgrade to NFS v3 support.

I don't know if there's any demand for NFSv3 on the old stack? Our PPC MVMExxxx boards have RAM ranging from 64MB to 256MB and more. Is anyone using the 68k vme boards where having enough RAM could be an issue?

Cheers,

-Matt

On Tue, Feb 11, 2020 at 10:55 PM Heinz Junkes <junkes at fhi-berlin.mpg.de> wrote:

Hi, Matt,

I have been using the libbsd TCP/IP stack in RTEMS5/EPICS7 since the end of last year.
I have already had some success with it, such as a "standard" /etc/rc.conf (dhclient.conf, …)file(s)
and e.g. initialization of Ethernet interfaces via DHCP. This looks quite good so far, but still has
many problems when using EPICS.
(E.g. I have not yet managed to ask the DHCP-server for dhcp-option-129 etc.)

But I think it is the right way for the future.

There are still missing things like

NTP (I am trying to integrate ptp2 now)
NFSv3 (here I still have to use the stuff from Till)
…
there are also problems with the support of PCI/VME ... (at least for my MVMExxxx boards)

I think it's the right way to go for this kind of stuff on FreeBSD and I would like to participate
in funding in this direction.

Viele Grüße Heinz
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> On 11. Feb 2020, at 20:46, Matt Rippa <mrippa at gemini.edu> wrote:
>
> Hello EPICS/RTEMS users,
>
> Back in 2017 there were some emails in the EPICS and RTEMS community about requesting support for an RTEMS NFSv3 client . We're getting increasing requests from our IT department to support this but don't see an easy way forward. We're running RTEMS 4.10.2 and NFSv2 is currently working and supported by default with a CentOS 6 file server. Moving to CentOS 7 we're getting push back supporting NFSv2. It's not enabled by default and we have to configure it. Our IT department believes the ability to enable NFS v2 on CentOS7 is a bug and it may not function properly after routine maintenance on a CentOS7 machine. This may be related to [1] below. A few questions:
>
> 1. Is there any risk manually configuring a CentOS7 nfs server to use version 2 via /etc/sysconfig/nfs ?:
>
> Config changes to /etc/sysconfig/nfs:
> MOUNTD_NFS_V2="yes"
> RPCNFSDARGS="-V 2"
> RPCMOUNTDOPTS="-V 2"
>
> 2. Do you know if CentOS 8 continues to support NFSv2, even if you have to configure it?
>
> 3. Do you know if/when we'll hit a hard stop with NFS v2 support on CentOS?
>
> 4. Gemini may be able to find some funding for the development of an NFSv3 client on RTEMS. Are other sites interested in pursuing this and sharing the cost?
>
> Aloha,
> -Matt Rippa
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1452461