Change docker device storage?


(adamprocter) #1

I didnt realise but my RHEL ended up setting up docker with devicemapper and somehow i was able to set up discourse. But I now cant update as discourse now is warning me. So I want to change to overlay2 or aufs.

Use the OverlayFS storage driver | Docker Documentation

I am super new to this and although I edited the daemon.json file I cant change to another storage as I think my kernel is too old. When I put in new info docker wont start but using storage as devicemapper still then it will…

Containers: 2
Running: 1
Paused: 0
Stopped: 1
Images: 20
Server Version: 1.12.1
Storage Driver: devicemapper
Pool Name: docker-253:2-67169354-pool
Pool Blocksize: 65.54 kB
Base Device Size: 10.74 GB
Backing Filesystem: xfs
Data file: /dev/loop0
Metadata file: /dev/loop1
Data Space Used: 14.11 GB
Data Space Total: 107.4 GB
Data Space Available: 57.34 kB
Kernel Version: 3.10.0-514.26.2.el7.x86_64
Operating System: Red Hat Enterprise Linux Server 7.3 (Maipo)
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 3.844 GiB

So I though I could update the kernel and then Json file might allow overlay2 so I tried sudo yum update kernel but terminal just seems to get stuck and doesnt appear to update anything…

Some basic tips would be good. Am happy to reinstall docker (but I need to use CE) and I need to keep RHEL

Thanks in advance


How to change storage backend in Docker
(Sam Saffron) #2

Since this is docker specific I recommend you both search and possibly post on https://forums.docker.com/


(adamprocter) #3

thanks - RHEL would not support a kernel high enough to do the conversion,
At the moment I have suppressed device mapper check so site is up and running for now and am hoping to migrate to a new Ubuntu Server 16.04.3 LTS VM instead as soon as my IT people give me approval. thanks for all the help


(adamprocter) #4

Moved to new server with Docker-CE , AUFS and Ubuntu LTS - very happy :smiley:
(got some oddness with Emoji but everything else seems to be working after restoring backup)


(Tarek Loubani) #5

Hello all,

For those who wish to change the docker device storage, I wrote a little guide that hopefully helps: