On Wed, Dec 07, 2022 at 07:53:26PM +0000, Glenn Cooper wrote:
>
> CERN and Fermilab jointly plan to provide AlmaLinux as the standard distribution for experiments at our facilities ...
>

I think "too late, too little". The ship has sailed and many people switched to Ubuntu.

Switching "back" is possible if CERN and FermiLab offer of "provide AlmaLinux" provides more
than a download mirror, but also addresses problems:

- device drivers arbitrary removed from RHEL kernels. we wish to continue to use those devices (specifically, "obsolete" PCIe RAID controllers) and we want to hear that arbitrary removal of device drivers will not continue into the future.
- device driver support for current hardware (specifically, laptops, but also latest AMD CPUs). historically RHEL was always behind Ubuntu in hardware support.
- 64-bit ARM supoprt. As I understand it was removed from RHEL, so AlmaLinux has to restore/backport it back? indefinitely into the future?
- 32-bit ARM support. I do not see an AlmaLinux download. So all 32-bit ARM hardware (RPI3s, FPGAs, etc) will run Debian/Ubuntu, breaking OS commonality
- 32-bit Intel support. We still have hardware with 32-bit Intel CPUs, it will have to run Debian/Ubuntu, breaking OS commonality.
- 3rd part hardware and software vendor support (specifically, CAEN). In recent years, I see many vendors dropping RHEL support while keeping Ubuntu/Debian support. CERN and FermiLan must work with the vendors to reverse this trend.
- integrated ZFS support, boot from ZFS, install to ZFS (including mirrored boot disks, mirrored EFI, bootloader, etc)
- NFS-Root support. Last I tried, RHEL-8 would not NFS-boot without major effort.
- NIS support. ("LDAP need not apply"), scheduled for removal in RHEL, still works just fine in Ubuntu/Debian.
- confusion of "streams", "split repositories" and other RHEL innovations/complications.
- "GCC is always 1 version behind Ubuntu, nothing compiles", "python is always 1 version behind Ubuntu, all scripts do not run"
- upgrade from version N to N+1 through reinstall only. RHEL 6-to-7, no go, 7-to-8 with difficulty, 8-to-9 does it work as well as "seamless" upgrades of MacOS? Will stay working for 9-to-10 and so forth? We still run SL6, "upgrade by reinstall" to AlmaLinux or to Ubuntu? Hmm?

OS commonality is the serious issue here.

In DAQ systems of recently built experiments, ARM boxes outnumber x86 boxes by a factor 5-10 (FPGA, RPI, etc). If RHEL/AlmaLinux cannot run on all of them, there is the good question, "why run RHEL on the one x86 DAQ box, why not run Ubuntu everywhere?". At CERN. having DAQ and online run on Ubuntu, but distributed offline analysis run on RHEL is an unwelcome complication.

Bottom line. Run Ubuntu/Debian everywhere, why bother with "RHEL on a few boxes, Ubuntu/Debian everywhere else".

P.S. Some users are comfortable with RHEL, they know how to use "yum", etc. Well with recent RHEL "yum" is replaced by "dnf", so that argument "for RHEL" is out the window now.

-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada