Re: Docker containers

From: Robert Klemme <>
Date: Wed, 31 Aug 2016 19:33:14 +0200
Message-ID: <>

[Quoted] 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.

[Quoted] We use that successfully for a cloud service that requires SDN.

> Colour me skeptical abut their (Docker) claims
> of efficiency.

[Quoted] [Quoted] 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.)

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

[Quoted] 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'.

[Quoted] 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.



remember.guy do |as, often| as.you_can - without end
Received on Wed Aug 31 2016 - 19:33:14 CEST

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