Re: [atomic-devel] Storage for system containers

[Giuseppe Scrivano <gscrivan redhat com>]

Daniel Walsh <dwalsh redhat com> writes:

> On 04/24/2017 01:56 PM, Dusty Mabe wrote:
>> NOTE: please reply-all when responding to this message
>>
>>
>> In Fedora Atomic Host if we use system containers as advertised
>> we end up using `atomic pull --storage ostree` which by default
>> throws images into /var/lib/containers/atomic/. This is on the
>> root filesystem which may be undesirable.
>>
>> Since in Fedora 26 the new version of container-storage-setup allows
>> us greater control over a "CONTAINER_ROOT" should we consider trying
>> to make sure both ostree storage and docker storage get placed under
>> that CONTAINER_ROOT?
>>
>> The current default [1] is to just mount the CONTAINER_ROOT on
>> /var/lib/docker.
>>
>> Dusty
>>
>> [1] https://src.fedoraproject.org/cgit/rpms/docker.git/tree/docker.spec?h=f26#n535
>>
> Perhaps we should just mount a partition at /var or move
> /var/lib/docker to /var/lib/containers/docker and make a symbolic link
> from /var/lib/docker-> /var/lib/containers/docker.

Mounting a partition at /var wouldn't work with system containers.

System containers are stored in the OSTree storage and on Atomic Host
they are checked out to /ostree/deploy/$OS/var/lib/containers/atomic/ so
that the checkout and the OSTree storage are on the same file system.
This is required to use hard links instead of copying files from OSTree.

Regards,
Giuseppe