Re: [atomic-devel] Storage for system containers

[Dusty Mabe <dusty dustymabe com>]

On 04/27/2017 08:51 AM, Daniel Walsh wrote:
> On 04/27/2017 06:44 AM, Giuseppe Scrivano wrote:

>> 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
> 
> Thanks for giving us a clue.   This breaks the assumptions that spawned 
> this conversation.

yes it does break the assumptions

> 
> We want to keep system containers on the same file system as /usr, and 
> since we use OSTRee
> 
> and most system containers will match the arch, then we should see a lot 
> of sharing so much smaller
> 
> disk usage then if they were standard docker images.   Dusty what do you 
> think?  I guess we should think about increasing the size of the "root" 
> file system to handle the need of system containers.
> 

hmm, i still don't like having possibly unbounded use of root FS for system
containers - if not much is shared then a lot more space could be used.

i'm going to show how little I know with this question, but would it be possible
to have a separate partition for system containers that was essentially xfs + an 
overlayfs of the host filesystem?