Re: [gentoo-user] Re: Get off my lawn?

[Andrew Savchenko]

On Sat, 17 Jan 2015 21:04:44 -0500 Rich Freeman wrote:
> Speak for yourself. :)  I did comment on my thoughts in this area in
> Donnie's thread.  Gentoo (IMHO) tends not to be the best distro for
> doing anything in particular.  I find that its best feature is that it
> is reasonably good at doing just about anything - it is a
> jack-of-all-trades.

I can't agree with you here, though your position have a rationale.
I see Gentoo as a Universal Constructor (UC) which may be used to
whatever specific needs Linux can be used at all.

In general UC pros is ability to create setup suitable for every
specific need, but cons is maintenance cost to create and update
such setup. Also creating and maintaining UC-powered setups rises
general professional level of system architect or amdin doing the
job.

So everything comes to how much user needs deviate from what
already existing binary distributions provide. If user needs are
perfectly satisfied with some binary distro, using Gentoo will only
raise maintenance costs. But if users demands something hardly
achievable with other (binary) distributions, then this is a good
place for Gentoo.

From my own experience I can point three directions where Gentoo
was and is reasonably the best choise for our needs (mine or my
colleagues):

1) HPC. When it comes to scalable tasks and large amount of
hardware, even small performance gain results into huge saving of
costs. On our first cluster we replaced CentOS by carefully
tuned Gentoo and performance gain was about 30-50% depending on
scientific application (please note I'm talking about real
applications and not about synthetic tests like linpack). With
hardware costs about million of dollars, 30% performance gain
results in a great saving. Price for that was much longer time for
initial setup (many weeks instead of many days), but it was
still less then time required to setup hardware itself and all
auxiliary engineering systems.

An interesting observation here is that average software update
cost of Gentoo is smaller that one of RH-based systems we used
before. While it is easier to update RH-based solution within the
same branch, then Gentoo setup, it is a complete nightmare to
upgrade from one branch to another, e.g. from RHEL4 to RHEL5. I've
gone through such update in the past an it is much worse than remove
everything and install from scratch, including all user
applications. As for Gentoo, all updates are equal: they bring some
build failures, runtime issues and compatibility problems, but to
a limited extent, which is handleable easy enough by prepared team.

2) High security servers. We have some systems dedicated to a very
specific needs where security demands are extreme. Hardened Gentoo
is the best solution here, since we can strip down such system close
to an absolutely possible minimum and protect that minimum by all
means (hardened toolchain and flags, PaX, SELinux and so on). Of
course, on top of then containers may be use to isolate different
daemons and so on...

3) Individual interested in getting every bit of performance
possible from own hardware. Frankly this was the reason why I
switched to Gentoo from RH about 8 years ago. I just tired to
rebuild each time a significant part of packages with custom flags
and configure options. Gentoo is much better suited for this task.
And as a result 13 years old hardware is still usable to watch 720p
and most of 1080p videos (without GPU hardware decoding). A
byproduct of such interest is a deep understanding of system
internals, which is a great result on its own.

Best regards,
Andrew Savchenko