[Devel] 4.14.7-vz8.1.4

[Konstantin Khorenko]

Hi Alexey,

On 04/24/2018 11:28 AM, gremlin at gremlin.ru wrote:
> Good ${greeting_time}, colleagues!
>
> Yesterday I've pulled fresh sources and, before letting the vz8
> to run in the test environment (and in the preprod on success),
> had a brief look at it.

i guess you mean vz7 for real use even you are talking about not a production, but semi-production,
"stable-4.14" branch is a development branch, not tested at all and
it's not clear if it will be ever more or less stable before RHEL8 is out.
We just do preparation work for RHEL8, rewrite pieces of code, etc,
not setting a goal to make it stable.


> Of course, the best and the most wise decision was the move to
> the most recent longterm-supported kernel. However, there are
> other changes, which don't seem that wise:
>
>
> 1. No beancounters.
>
> It was one of the best sources of diagnostic information about
> what happens inside of VE, so I guess many administrators would
> like to either get it back or have this information available
> from some other source.

Just not finished working on it.
Keeping custom accounting - what "ubc" was initially - is a dead end,
we use more and more standard accounting (memcg primarily),
but keep ubc interface for those who used to it.

We've started this work in vz7 (RHEL7-based) and will continue it in vz8 (RHEL8-based).

BTW, which exactly ubc parameters you really need and use?


> 2. No simfs.
>
> Well, ploop has some advantages... However, I'd like to get a
> simple recipe for _shrinking_ the VE's filesystem on the fly,
> while keeping it running.

simfs work in the very same way as in vz7 now.
And simfs works in 4.14-based vz kernel even right now,
even more - a CT can be started on simfs only now. :)

"simfs" in vz7 is just a bindmount and lacks quota - that's another question.
When we developed vz7 i asked for a volunteer to implement it,
it seems to be quite easy, wrote a brief plan how to do that,
but no one answered, so...

Have a nice day.

--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

> Alas, with the lack of these features most of your users would
> very likely stuck at vz6, which is simple and effective (and
> requires only two userspace packages, vzquota and vzctl).