Re: Upgrading EPICS base from 3.15.6 to 7.0.x

[Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Hi Abdalla,

I have nearly all of my production IOCs on RHEL 9 now, and I did not have any significant issues moving from CentOS 7 and CentOS 8.  Many other APS beamlines are also running RHEL 9.

Mark

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>
Sent: Sunday, September 1, 2024 12:54 AM
To: tech-talk at aps.anl.gov <Tech-talk at aps.anl.gov>
Subject: RE: Upgrading EPICS base from 3.15.6 to 7.0.x

 

Unfortunately, we do not have enough resources to test EPICS base upgrades, nevertheless I always thought the effort for the upgrade will be minimal, I think mainly because we use standard modules and our RPM build is scripted in a way to be somehow automated and with the recent deployment of docker the process should go smoothly.

 

We tried Rocky Linux 9.1 back when it first launched during the RedHat drama on CentOS, I faced some build issues and could not solve them withing the time frame we had back at that time so we decided to go with Rocky 8 which went very smooth, but it would be great hearing about experiences running EPICS in production under RedHat/Rocky Linux 9.

 

Best Regards,

Abdalla.

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Ralph Lange via Tech-talk
Sent: Monday, August 26, 2024 5:04 PM
To: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: Upgrading EPICS base from 3.15.6 to 7.0.x

 

On Mon, 26 Aug 2024 at 13:31, Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov> wrote:

 

Is it worth to upgrade to 7.0.x or just stay with the stable release and upgrade to 3.15.9?

 

Nowadays, 7.0 is the mainstream version.

Generally, it means better support, faster fixes, less work and less risk for future upgrades.

 

Will there be any advantages for upgrading to 7.0.x instead of 3.15.9?

 

Have a look at the release notes document for the current 7.0 to see what you'd be missing.

A lot.

The main advantage: your IOCs will (be able to) support pvAccess (PVA) - that means future-proofness out of the box. Even if you decide not to enable or not to use the PVA server on the IOCs from day one.

 

The IOC parts of EPICS 7 are highly compatible with the 3.15 series. If you're not actively running PVA, I would consider that step to be a low-risk migration.

(The longer you wait, the higher the risk, though.)

 

The reason for this question is while upgrading from CentOS 7 to Rocky Linux 8 I faced some build issues in some IOCs in which they build fine on CentOS 7 with the same base version, going to 3.15.9 solved the issue.

 

I'd side with Timo: If you can move to the latest 7.0 release, how would you justify not to?

Channel Access ensures compatibility. Migrate a few of your IOCs, run them for a while, then migrate more as you gain confidence.

 

Btw. The first installations have started moving to RedHat 9. Just saying...

 

Cheers,
~Ralph