CentOS - Feb 2021 - Transition test report going from CentOS8 to Debian 10.

On 2/4/21 1:23 PM, Warren Young wrote:
> On Feb 4, 2021, at 8:39 AM, Lamar Owen <lowen at pari.edu> wrote:
>> I posted a pretty complete rundown on the scientific linux users
mailing list, so I won't recap it all here.
> Link?
Yeah, I forgot to post the link... sorry about that.? Akemi beat me to 
it, so I'll not repost.? Thanks, Akemi!
>> the transition was not any more difficult, really, than moving from
CentOS 7 to CentOS 8.
> That?s not my experience.

I thought long and hard about it before posting to the CentOS lists, 
because I don't want to be perceived as advocating for a particular 
transition path.? I am exploring different paths, and I started with my 
own workstation.? Of course workstation needs are going to be some 
different than server needs; and thus I posted here to sincerely see 
others' experiences.? Thanks for the great information!
> I keep several of my packages running on CentOS and Debian (and more) and I
keep running into several common problems:
>
> 1. The package names are often different, and not always differing by an
obvious translation rule.  ...

This one I've run across, and yes the package name differences are 
annoying.? I did some cross-packaging myself back in the day, all on RPM 
systems, and I had to do special cases for SuSE since the package names 
are quite different there, too.? Why are they different?? Different 
naming standards developed at different times by different people with 
different ideas; I would consider it very odd if different distributions 
had identical package naming after going through such different paths.?? 
I consider this to be very minor in comparison to other items.
> 2. Some packages simply won?t be available.  Most often this happens in the
Debian ? CentOS direction, but I?ve run into cases going the other way. ...

Yes, true.? True going from C7 to C8, too, especially if you rely on 
third-party repositories for packages.
> 3. Debian adopted systemd, but it didn?t adopt the rest of the Red Hat
userland tooling.  For instance, it?s firewalld on CentOS, UFW on Ubuntu, and
raw kernel firewall manipulation on Debian unless you install one of those two. 
And then, which?
That one is more serious for the server than the other two, for sure.? 
If migrating from CentOS I would probably go with firewalld.? I haven't 
decided yet in my evaluations.? But I put an ACL on the Cisco 7609's 
here on all server-bound traffic, so not yet an important consideration 
for me.? But it will be soon enough.
> 4. Network configuration is almost entirely different unless you turn off
all the automation on all platforms, in which case you might as well switch to
macOS or FreeBSD for all the good your muscle memory and training will do you.

Again I started with my workstation, and since I chose a GNOME install I 
got all the NetworkManager tooling; once NM is in control there aren't 
too many differences.? Red Hat and Debian chose different paths for 
system configuration information, that much is for sure.? But I try to 
not EVER use strict muscle memory in a sysadmin role, since that is 
guaranteed to break on CentOS version upgrades too, and I have too many 
different systems to rely on muscle memory, although I do find myself 
using that out of habit.? Constantly doing things differently keeps me 
sharp, hopefully, at least.? YMMV.
> I?m not saying ?don?t do it,? but to say it?s as smooth as from CentOS 7 to
8?  Hard sell.
On my workstation with my workload it hasn't so far been that big of a 
deal and was less of a hassle than what C7 to C8 was; that is my 
specific workstation and my specific workloads, of course.? I am getting 
ready to take an older internal server that is on CentOS 6 (yes, I know, 
EOL etc etc) to Debian 10 as a test; I had planned to take to CentOS 8 
in early December, at least until the news hit, causing me to hold it up 
until I had a better idea of the issues.? I'll know a whole lot more 
after that is done.

> ... it?s always *something.*
True that.


I will say that thus far my experience is mostly on the workstation, 
although I did set up a couple of test servers.? One is an old Dell 
PE1950; had no issues with the Red Hat-unsupported Dell PERC RAID 
controller and the C8-removed PCI IDs from the megaraid_sas driver.? The 
other one is....... well, INTERESTING: for grins and giggles I installed 
the 32-bit version on an ancient IBM eSeries x330 rocking dual Pentium 
III-S? 1.4GHz Tualatins with a full 4GB of RAM and dual 146GB U320 SCSI 
drives - maximum performance you'll get from a Pentium III (and almost 
as good as a much newer 64-bit Netburst-based Xeon at 3.2GHz; Byte 
Unixbench on the Tualatins at 324.6; on the Noconas 491.4, at over twice 
the clock speed, too). And it's fun to just be able to say I have one of 
the most maxxed-out Pentium III-S systems you'll find, at least without 
overclocking or going past a dually.? YMMV, and you might not think it 
so much fun, but you'll see my idea of computer fun in my SL-users list 
post when you get down to the paragraph about the TRS-80 emulators.....

Le 05/02/2021 ? 17:03, Lamar Owen a ?crit?:
> I thought long and hard about it before posting to the CentOS lists,
because I
> don't want to be perceived as advocating for a particular transition
path.
I found your post highly interesting, even though I chose a different path:

https://blog.microlinux.fr/migration-centos-oracle-linux-cas-pratique/

Cheers,

Niki

-- 
Microlinux - Solutions informatiques durables
7, place de l'?glise - 30730 Montpezat
Site : https://www.microlinux.fr
Blog : https://blog.microlinux.fr
Mail : info at microlinux.fr
T?l. : 04 66 63 10 32
Mob. : 06 51 80 12 12

On Feb 5, 2021, at 9:03 AM, Lamar Owen <lowen at pari.edu>
wrote:
> 
>> 1. The package names are often different, and not always differing by
an obvious translation rule.  ...
> 
> I consider this to be very minor in comparison to other items.
If you?re making a wholesale transition, sure, but when you?re maintaining a mix
of systems and you know what you?re trying to accomplish but can?t remember the
exact one of six different incantations for accomplishing that on the platforms
you maintain, it?s enough to frost one?s cookies.

It?s gotten bad enough for me that I now maintain a private wiki listing
instructions for how to set up a new system, alternate top-level sections giving
translations of the primary platform?s instructions for each platform I have to
manage.  Bleah!

(I mined that wiki to compose my prior reply.  Real-world experience here.)
>> 2. Some packages simply won?t be available.  Most often this happens in
the Debian ? CentOS direction, but I?ve run into cases going the other way. ...
> 
> Yes, true.  True going from C7 to C8, too, especially if you rely on
third-party repositories for packages.
Yes, I lost many packages moving from C7 to C8, too.  However, I?d prefer to
hold tight to *one* bag of problems rather than gather several bags of problems
unto my bosom. :)
>> 3. Debian adopted systemd, but it didn?t adopt the rest of the Red Hat
userland tooling.  For instance, it?s firewalld on CentOS, UFW on Ubuntu, and
raw kernel firewall manipulation on Debian unless you install one of those two. 
And then, which?
> 
> That one is more serious for the server than the other two, for sure.
And realize that firewalld is just an example, not the full scope of the
problem.  Solve that one across platforms, and you?ve got several more to deal
with next.
> If migrating from CentOS I would probably go with firewalld.  I haven't
decided yet in my evaluations.  But I put an ACL on the Cisco 7609's here
How does fobbing the problem off on Cisco help in today?s ?deny everything by
default? world?  Unless you?re lucky enough to be using binary packages that
take care of all of this for you, you?re still going to have to manually punch a
hole in the firewall for some service or other, which means you?ve now got to
learn to do that on every platform you?re supporting, because it probably won?t
be the same way on any two of them.
> I have one of the most maxxed-out Pentium III-S systems you'll find
Good in winter for an under-desk system, exhaust fan pointed at your frozies
toesies. :)