CentOS Stream 9 Now Available To Live On The Bleeding-Edge Of RHEL9

[CommunityMember]

If I have understood well:
Fedora = RHEL Beta
CentOS Stream = RHEL RC

As with any analogy, the comparison is never exactly perfect at the detail level. I tend to think of it more like git branches (which is how I suspect they are managing it).

* Fedora Rawhide = main branch (somewhat constant development)
* Fedora Fxx = branched main at point in time
* CentOS [n.PRE, or n.BETA if you prefer] = a branched Fedora Fxx (with specific cherry picks/back ports and EL additions)
* CentOS [n] Stream = regular review of and cherry picking or back porting of important upstream features/fixes (sometimes from Fedora, sometime upstream, sometimes RH/EL specific), with some validation, but perhaps a slighter lighter touch for regression testing (RH has a large number of systems that are "certified", and I suspect full validation across all of those configuration are not required, just various functional testing across a wide verify of such systems, before getting released into Stream), with the early availability of those features and/or fixes in what will become the next EL [n.m].
* EL [n.m] = a branched CentOS [n] Stream at some point in time for RH EL customers (with future targeted cherry picking and back ports for critical fixes). EL [n.m] before official release tends to get far more extensive regression testing across systems and environments, and breaking changes (from EL [n.m-1] to EL [n.m]) need specific justification and documentation.

The Alma, Oracle, Rocky derivatives take EL [n.m] as their base, add their own specific sauce to the recipe, and release the result as their clone, although, perhaps other than Oracle, I doubt any do as extensive regression testing across any certified platforms that RH does (few companies have Z series systems to test with, and emulation is not always good enough).

[CommunityMember]

At the present point in time there is no official migration path from Stream 8 to Stream 9 without reprovisioning.

While RH has offered migration scripts for their direct customers (using leapp), even before the CentOS refocus the CentOS team never implemented anything equivalent (as you say, it is not an easy task to get things right due to the large variability in how things can be interestingly configured, although there have been various docs that provide a possible solution for some of the people some of the time, and your distro-sync solution is among them).

These days, the usual recommendation is that one use infrastructure configuration tools (ansible, chef, puppet, whatever) to just reinstall and configure new instances as you wish (some use the term Infrastructure as Code). It can take some time to move towards that approach, but there are long term benefits.

[Developer12]

I'm still annoyed they're dropping the bottom CPU feature level for this. It's pointless unless you drop more levels because you'll only really see a benefit from the late ISA additions. They don't want to do that though, because it would force them to split their packages into "older" and "very new" streams. This is really just a deprecation. They aren't doing it for the benefit of performance.

Meanwhile everyone running older gear (I'm running a K10 and my university runs K8s) is going to be forced to abandon them if they haven't already. At this point, unless Rocky compiles for a wider range of feature levels, I'm going to be leaving rhel/cent/etc for good. It won't be physically possible for me to run it anymore.

[SteamPunker]

Is is so disappointing to see "CentOS" and "Bleeding-Edge" even being mentioned in the same sentence.

Seriously, I appreciate all the contributions both IBM and Red Hat have made to Linux and Open Source over the years (nay, decades), but acquiring CentOS and then effectively killing it was not cool, and caused a lot of problems for a lot of people and organizations. Serious goodwill was squandered here, sorry to say.

[JPFSanders]

I Have three mission-critical machines running CentOS 8 (Stopped deploying CentOS 8.x when the debacle started waiting for the dust to settle).

At this point after reading the article, I'm not sure whether I will convert them to RH8 or Alma/Rocky, or even - god forbid - Oracle next January (oh boy I can't believe what I just wrote even Oracle looks like a better fit), I need to decide. However something is for sure, next machine I deploy for mission critical (where customers aren't willing to pay for RH) is going to be Debian based not CentOS.

And the reason is simple, good old CentOS had two qualities: RHEL compatible with mainstream RHEL and Stable with 10 year support. Those two advantages gone and Debian has the upper hand as it allows me to migrate to the next release, very rarely have I had trouble upgrading to the next stable release and updates don't bring surprises.

I find mesmerising that after all these months I still have trouble understanding what is CentOS Stream exactly, and if could be trusted to to do "dnf update -y" without causing me trouble at 3:00AM because if it does/can cause issues... what good is CentOS Stream for?, testing labs?

We got told CentOS Stream would be "stable" betas of RHEL 8.x-based and now out of the blue is based on RHEL 9-beta.... Maybe I'm being thick here, and I'm so confused right now about the whole ordeal, but CentOS Stream doesn't look attractive to me to build stable platforms.

[szymon_g]

jeez, the link doesn't work with wget (and no, i cannot be arsed to 'hack' it), and there is no torrent for it. do they actually want people to download it or not?

[Setif]

Meanwhile everyone running older gear (I'm running a K10 and my university runs K8s) is going to be forced to abandon them if they haven't already. At this point, unless Rocky compiles for a wider range of feature levels, I'm going to be leaving rhel/cent/etc for good. It won't be physically possible for me to run it anymore.

RHEL 8 and its clones are supported until 2029. You are not forced to upgrade to RHEL 9

[okapi]

Centos Stream 9 has already been available for several weeks.

I've been running it in a VM for testing, to ensure our ansible playbooks will be ready for RHEL 9 and to experiment with FreeIPA. While it's a pity they dropped classic Centos, I see the existence of stream as being a useful thing in the long term.

[mroche]

jeez, the link doesn't work with wget (and no, i cannot be arsed to 'hack' it), and there is no torrent for it. do they actually want people to download it or not?

The link is a MirrorManager link, as CentOS is now using Fedora's mirroring infrastructure. If you're using wget, you should be able to get it with wget --content-disposition "quoted-link". The quotes are necessary. If you have the path=<> as the last parameter, you don't need the --content-disposition flag*.

* Technically you don't need it for the provided order, but the outfile name will be mangled.

Cheers,
Mike

[browseria]

...I find mesmerising that after all these months I still have trouble understanding what is CentOS Stream exactly, and if could be trusted to to do "dnf update -y" without causing me trouble at 3:00AM because if it does/can cause issues... what good is CentOS Stream for?, testing labs?

We got told CentOS Stream would be "stable" betas of RHEL 8.x-based and now out of the blue is based on RHEL 9-beta.... Maybe I'm being thick here, and I'm so confused right now about the whole ordeal, but CentOS Stream doesn't look attractive to me to build stable platforms.

CentOS Stream is simply the staging area for the next minor release of RHEL. There are now two: CentOS Stream 8 and CentOS Stream 9. CentOS Stream 8 will continue until 2029, CentOS Stream 9 will continue until 10 years after RHEL 9.0 is released. If you never run "dnf -y update" except when then next point release is ready, it would behave EXACTLY like it did when you ran plain CentOS 8, CentOS 7, CentOS 6, etc. Absolutely NO difference. The only thing that has changed is that if you care to, you can run "dnf -y update" more often and have it result in more changes quicker. That is all. It still is "RHEL compatible with mainstream RHEL" (literally it IS RHEL) and "Stable with 10 year support". None of that has changed.

When RHEL 10 is ready to be branched off from fedora, a CentOS Stream 10 will be created that behaves the same way as CentOS Stream 9 and CentOS Stream 8. It will also live for 10 years.

If you really want to to wait and get the point release updates last, there is no need to switch to Debian, Alma & Rocky Linux have got you covered.

If you choose to stay with CentOS Stream and to run "dnf -y update" more than roughly once a quarter, you should expect the experience to be similar to what happens when you run "dnf -y update" on a branched version of Fedora. Will it cause you issues at 3:00AM? It's not impossible, but it's also easy to roll back to the last known good, or to wait until 8:00AM