2. SLF6: Scientific Linux Fermi 6
SL7: Scientific Linux 7
C8: CentOS Linux 8
Thanks to Ben Morrice of CERN for the calendar format idea.
The Plan as of November 2020
9/10/2022
2
2020
H1
2020
H2
2021
H1
2021
H2
2022
H1
2022
H2
2023
H1
2023
H2
2024
H1
2024
H2
2025
H1
2025
H2
2026
H1
2026
H2
2027
H1
2027
H2
2028
H1
2028
H2
2029
H1
SLF6
SL7
C8
Linux Options
3. On December 12, 2020, CentOS announced:
“The future of the CentOS Project is CentOS Stream, and over the
next year we’ll be shifting focus from CentOS Linux, the rebuild of
Red Hat Enterprise Linux (RHEL), to CentOS Stream, which tracks
just ahead of a current RHEL release. CentOS Linux 8, as a rebuild of
RHEL 8, will end at the end of 2021.”
CentOS Change
9/10/2022
3 Linux Options
4. SLF6: Scientific Linux Fermi 6
SL7: Scientific Linux 7
C8: CentOS Linux 8
CS8: CentOS Stream 8
CS9: CentOS Stream 9
So, as of December 2020:
9/10/2022
4
2020
H1
2020
H2
2021
H1
2021
H2
2022
H1
2022
H2
2023
H1
2023
H2
2024
H1
2024
H2
2025
H1
2025
H2
2026
H1
2026
H2
2027
H1
2027
H2
2028
H1
2028
H2
2029
H1
SLF6
SL7
C8
CS8
CS9
Linux Options
5. • What is CentOS Stream, exactly?
• Implications of this change
• Possible options, pros and cons
• Path forward
For discussion today:
9/10/2022
5 Linux Options
6. • Not a beta version: Each package that goes into Stream has
gone through Red Hat’s QA process and will appear as-is in
the next RHEL minor version release.
• Key differences from CentOS Linux:
– 5-year life cycle (vs. 10 years for CentOS Linux 7)
• Matches “Full Support” phase of RHEL
– More frequent, smaller updates: Once they pass QA, new
versions of packages are released immediately to CentOS
Stream. For CentOS Linux (and RHEL), they’re collected
internally until the next minor (dot) version is released.
– Adds a mechanism to feed changes into RHEL
CentOS Stream
9/10/2022
6 Linux Options
7. What do you need in a Linux operating system?
• Lifetime: Is 5 years enough?
• Support for architectures other than x86, e.g., ARM?
• Stability (lack of change) vs. recent software (more change)?
Requirements
9/10/2022
7 Linux Options
8. We are working with CERN to arrive at a common decision.
Options currently considered:
• Use CentOS Stream
• Use a different RHEL rebuild, similar to the original CentOS
Linux: Springdale Linux, Rocky Linux, AlmaLinux, …
• Other options can be considered for the long term, but aren’t
feasible in the next 1–few years.
Options
9/10/2022
8 Linux Options
9. With any of the above: Aggressive containerization—run
everything in containers, or as much as possible. Then the
underlying OS will matter less.
With Stream (especially, though not exclusively): Further push
for CI/CD to mitigate more frequent changes in OS.
Options—comments
9/10/2022
9 Linux Options
10. CentOS Stream
Pros:
• Supported by Red Hat & CentOS
• Very similar to CentOS Linux
• Quick availability of new package versions
Cons:
• 5-year life cycle
• Loss of trust in RH/CentOS
• Possible compatibility questions for applications: If a 3rd-party
application is certified for RHEL, will it work on Stream (and
vice versa)?
Discussing Options
9/10/2022
10 Linux Options
11. RHEL rebuilds/clones
Pros:
• 10-year life cycle, matching RHEL (assuming Red Hat
continues to release software as they have)
• We (FNAL, CERN, HEP) could contribute and have influence
Cons:
• Still depend on Red Hat
• Except for Springdale, no track record, so hard to judge
stability and support
Discussing Options
9/10/2022
11 Linux Options
12. • Where 8 is needed now, run CentOS Stream 8
– Many experiments may be able to go directly from SL7 to
Stream 9
• Watch progress of rebuilds (Rocky, Springdale, Alma, …), do
some testing
• Migrate to either Stream 9 or a rebuild, depending on our
experience with Stream and on how the rebuilds have
developed.
Longer-term plan: Consider more fundamental changes
(Debian? A new HEP build from sources? Other distributions?)
Near-term Plan
9/10/2022
12 Linux Options
15. Main Stream download page:
https://www.centos.org/centos-stream/
Goes to a list of mirrors, including:
http://linux-mirrors.fnal.gov/linux/centos/8-stream/isos/x86_64/
Fermilab customizations (Kerberos, etc.):
https://linux-mirrors.fnal.gov/linux/fermilab/centos/8/notes.html
Installing CentOS Stream 8
9/10/2022
15 Linux Options
