Re: Docker containers

From: Mladen Gogala <>
Date: Wed, 31 Aug 2016 19:32:47 -0000 (UTC)
Message-ID: <>

[Quoted] On Wed, 31 Aug 2016 19:33:14 +0200, Robert Klemme wrote:

> On 31.08.2016 10:58, Andy wrote:

>> Mladen Gogala wrote:

>>> Docker containers are light-weight virtual machines which are
>>> allegedly much more efficient than the traditional VM's, created by
>>> VMWare or Hyper-
>>> V. I don't see Docker being present in any significant numbers in my
>>> client environments. Cloud service providers are still using VMWare,
>>> Hyper-V and they don't seem to being present in any significant
>>> numbers,
>> I've never seen or heard of them in use for anything, let alone
>> production systems.

> We use that successfully for a cloud service that requires SDN.
>>  Colour me skeptical abut their (Docker) claims
>> of efficiency.

> VMWare and the likes simulate a complete machine including simulated
> hardware. That is why you can run a Windows in a VM that sits on a
> Linux host. Compare that to LXC and Docker where there is just one
> kernel and kernel features are used to restrict access, show only a part
> of the filesystem (chroot like), assign virtual network interfaces etc.
> There is much less overhead. (And of course this comes at a price: you
> cannot run something inside a Docker container which requires a newer
> kernel than the host has.)

But you do lose portability. I very much doubt that Docker container, created for the Linux kernel would work on Winduhs.


>>> I believe that any virtual machine, not only Docker, is a complete
>>> nonsense when it comes to RAC.
>> Agreed.

> Apart from testing maybe.
>>> So, is an Oracle database in a Docket container practical or just
>>> another marketing fad, like agile, DevOps and BAAS (Bug as a service)?

>> One thing it almost certainly could be described as is 'unsupported'.

> Which might be just a /slight/ hindrance for productive services that
> host important data... ;-)
> Still, it is also a hype and there is no point in running berserk just
> because someone asks for reasons why they do that. This is a warning
> sign that the decisions at that shop are made based on the wrong
> reasons. Shudder.
> Cheers
> robert

[Quoted] Actually, the person who responded with the most zeal told me that I should do that because Docker crossed the $1bn boundary.

Mladen Gogala
The Oracle Whisperer
Received on Wed Aug 31 2016 - 21:32:47 CEST

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