How can I use another directory to save built Docker containers? - docker

I am using Vagrant with Docker provision.
The issue is when I run my docker compose I fill up my VM disk space.
Here is what my file system looks like:
Filesystem Size Used Avail Use% Mounted on
udev 476M 0 476M 0% /dev
tmpfs 97M 3.1M 94M 4% /run
/dev/sda1 9.7G 2.2G 7.5G 23% /
tmpfs 483M 0 483M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 483M 0 483M 0% /sys/fs/cgroup
tmpfs 97M 0 97M 0% /run/user/1000
vagrant_ 384G 39G 345G 11% /vagrant
vagrant_www_ 384G 39G 345G 11% /vagrant/www
How can I configure Docker or Vagrant to use /vagrant directory?
(By the way I have not loaded Docker... This is why it's not 100% disk usage)

You can try to reconfigure the Docker daemon as documented here -> https://docs.docker.com/engine/reference/commandline/dockerd/#options. Use the -g parameter to change the root runtime path of the Docker daemon.
--graph, -g /var/lib/docker Root of the Docker runtime
As long as you are working on a local disk or SAN this would be a proper way to change the location of the Docker data including the images. But be aware, do not use NFS or another type of share because this won't work as of the used massive file locks. Somewhere on Github there is an issue about this.

Related

How to increase the size of /dev/root on a docker image on a Raspberry Pi

I'm using the https://github.com/lukechilds/dockerpi project to recreate a Raspberry Pi locally with Docker. However, the default disk space is very small and I quickly fill it up:
pi#raspberrypi:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 1.8G 1.2G 533M 69% /
devtmpfs 124M 0 124M 0% /dev
tmpfs 124M 0 124M 0% /dev/shm
tmpfs 124M 1.9M 122M 2% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 124M 0 124M 0% /sys/fs/cgroup
/dev/sda1 253M 52M 201M 21% /boot
tmpfs 25M 0 25M 0% /run/user/1000
How can I give move space to the RPi? I saw this issue, but I don't understand how that solution is implemented, or if it is relevant.
To increase the disk size, you need to extend the partition of the qemu disk used inside the container.
Start the docker to unzip rootfs and mounted it to an host path
docker run --rm -v $HOME/.dockerpi:/sdcard -it lukechilds/dockerpi
When the virtualized raspberry is up, you can stop it, running from the docker prompt sudo poweroff
Then you have the qemu disk in $HOME/.dockerpi/filesystem.img.
It could be extended with :
sudo qemu-img resize -f raw $HOME/.dockerpi/filesystem.img 10G
startsector=$(fdisk -u -l $HOME/.dockerpi/filesystem.img | grep filesystem.img2 | awk '{print $2}')
sudo parted $HOME/.dockerpi/filesystem.img --script rm 2
sudo parted $HOME/.dockerpi/filesystem.img --script "mkpart primary ext2 ${startsector}s -1s"
Restart the raspberry that will use the resized qemu disk with :
docker run --rm -v $HOME/.dockerpi:/sdcard -it lukechilds/dockerpi
Running from the docker prompt you can extend the root filesystem with :
sudo resize2fs /dev/sda2 8G
Finally the root is increased.
Following this df -h give :
Filesystem Size Used Avail Use% Mounted on
/dev/root 7.9G 1.2G 6.4G 16% /
devtmpfs 124M 0 124M 0% /dev
tmpfs 124M 0 124M 0% /dev/shm
tmpfs 124M 1.9M 122M 2% /run
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 124M 0 124M 0% /sys/fs/cgroup
/dev/sda1 253M 52M 201M 21% /boot
tmpfs 25M 0 25M 0% /run/user/1000
If the solution is indeed to resize /dev/root, you can follow this thread, which concludes:
Using the gparted live distro, I struggled for a little while until I realised that the /dev/root partition was within another partition.
Resizing the latter, then the former, everything works. I just gave the /dev/root partition everything remaining on the disk, the other partitions I left at their original sizes.

Give docker more diskspace for containers

I have a question. Our docker server was out of space for its containers so I gave it a bigger disk from 500GB to 1TB(its a vm) Ubuntu sees this correctily. If I do the command vgs I get this output:
VG #PV #LV #SN Attr VSize VFree
Docker-vg 1 2 0 wz--n- 999.52g 500.00g
But Docker still thinks it's out of space. I have rebooted the docker VM but still he thinks it's out of space. If I use the df -h command this is the output:
Filesystem Size Used Avail Use% Mounted on
udev 3.9G 0 3.9G 0% /dev
tmpfs 792M 8.6M 783M 2% /run
/dev/mapper/Docker--vg-root 490G 465G 0 100% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/xvda1 472M 468M 0 100% /boot
As you see the docker-vg still thinks its 490gb
I don't know where to look. can someone help me ?
You still need to extend your logical volume and resize the filesystem to use the larger logical volume.
First, with lvextend, I'm not sure if it works with /dev/mapper. If not, you can do an lvdisplay to list your logical volumes:
lvextend -l +100%FREE /dev/mapper/Docker--vg-root
With ext*fs you can then run a resize:
resize2fs /dev/mapper/Docker--vg-root
The command is similar for xfs:
xfs_growfs /dev/mapper/Docker--vg-root
With "docker system prune" you clean some space removing old images and other stuff.
If you want your container to be aware of the disk size change, you have to:
docker rmi <image>
docker pull <image>

Docker: How to store images and metadata on another filesystem?

This issue has been really giving me grief and I would appreciate some help.
Running docker 1.10.3 on a vanilla Centos7.1 box, I have two file systems, a 15gb dev/vda1 where my root and var/lib is and a 35gb /dev/vdc1 mounted on mnt where I would like to put my docker volumes/image data and meta data. This is for administration and management purposes as I am expecting the number of containers to grow.
Filesystem Size Used Avail Use% Mounted on
/dev/vda1 15G 1.5G 13G 11% /
devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 1.9G 8.3M 1.9G 1% /run
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/vdc1 35G 49M 33G 1% /mnt/vdc1
tmpfs 385M 0 385M 0% /run/user/0
Despite all my attempts, docker keep on installing and defaulting to place the Data Space and Meta data space onto the 15gb root volume. I have tried many solutions including ; http://collabnix.com/archives/5881 , How to change the docker image installation directory?, and more, all with no luck.... basically wither the docker instance does not start at or all it does with its default settings.
Would like some help either the settings required for Data and Meta data to be stored on /mnt/vdc1 or install docker as a whole on the drive.
Thanks in advance , bf !
--graph is only one flag. There is also --exec-root and $DOCKER_TMPDIR which are used to store files as well.
DIR=/mnt/vdc1
export DOCKER_TMPDIR=$DIR/tmp
dockerd -D -g $DIR --exec-root=$DIR

Ambiguity in disk space allocation for docker containers

I have two Physical machine installed with Docker 1.11.3 on ubuntu. Following is the configuration of machines -
1. Machine 1 - RAM 4 GB, Hard disk - 500 GB, quad core
2. Machine 2 - RAM 8 GB, Hard disk - 1 TB, octa core
I created containers on both machines. When I check the disk space of individual containers, here are some stats, which I am not able to undestand the reason behind.
1. Container on Machine 1
root#e1t2j3k45432#df -h
Filesystem Size Used Avail Use% Mounted on
none 37G 27G 8.2G 77% /
tmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda9 37G 27G 8.2G 77% /etc/hosts
shm 64M 0 64M 0% /dev/shm
I have nothing installed in the above container, still it is showing
27 GB used.
How come this container got 37 GB of space. ?
2. Container on Machine 2
root#0af8ac09b89c:/# df -h
Filesystem Size Used Avail Use% Mounted on
none 184G 11G 164G 6% /
tmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda5 184G 11G 164G 6% /etc/hosts
shm 64M 0 64M 0% /dev/shm
Why only 11GB of disk space is shown as used in this container. Even
though this is also empty container with no packages installed.
How come this container is given 184 GB of disk space ?
The disk usage reported inside docker is the host disk usage of /var/lib/docker (my /var/lib/docker in the example below is symlinked to my /home where I have more disk space):
bash$ df -k /var/lib/docker/.
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/... 720798904 311706176 372455240 46% /home
bash$ docker run --rm -it busybox df -k
Filesystem 1K-blocks Used Available Use% Mounted on
none 720798904 311706268 372455148 46% /
...
So if you run the df command on the same container on different hosts, a different result is expect.

Docker container drive does not match available hard drive space on host

I have loaded a new custom image into a remote RedHat 7 docker host instance. When running a new container, the container does not attempt to use the entire disk. I get the following is the output of a df -h on the container:
rootfs 9.8G 9.3G 0 100% /
/dev/mapper/docker-253:0-67515990-5700c262a29a5bb39d9747532360bf6a346853b0ab1ca6e5e988d7c8191c2573
9.8G 9.3G 0 100% /
tmpfs 1.9G 0 1.9G 0% /dev
shm 64M 0 64M 0% /dev/shm
/dev/mapper/vg_root-lv_root
49G 25G 25G 51% /etc/resolv.conf
/dev/mapper/vg_root-lv_root
49G 25G 25G 51% /etc/hostname
/dev/mapper/vg_root-lv_root
49G 25G 25G 51% /etc/hosts
tmpfs 1.9G 0 1.9G 0% /proc/kcore
tmpfs 1.9G 0 1.9G 0% /proc/timer_stats
But the host system has much more space:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_root-lv_root 49G 25G 25G 51% /
devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 1.9G 8.5M 1.9G 1% /run
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/mapper/vg_root-lv_home 9.8G 73M 9.7G 1% /home
/dev/sda1 497M 96M 402M 20% /boot
It seems as if docker is assigning the 9.8 gigs of the /home mapping to the entire drive of the container. So I am wondering if there is a reason I am seeing this?
The Problem
I was able to resolve this problem. The issue was not related to the volume that was being mounted to the container (ie It was not mounting the home volume as the root volume on the container). The problem occurred because docker uses device-mapper in RedHat to manage the file systems of it's containers. By default, the containers will start with 10G of space. In general, docker will use AUFS to manage the file systems of the containers. This is the case on most Debian based versions of Linux, but RedHat uses device-mapper instead.
The Solution
Luckily, the device-mapper size is configurable in docker. First, I had to stop my service, and remove all of my images/containers. (NOTE: There is no coming back from this, so backup all images as needed).
sudo service stop docker && sudo rm -irf /var/lib/docker
Then, start up the docker instance manually with the desired size parameters:
sudo docker -d --storage-opt dm.basesize=[DESIRED_SIZE]
In my case, I increased my container size to 13G:
sudo docker -d --storage-opt dm.basesize=13G
Then with docker still running, pull/reload the desired image, start a container, and the size should now match the desired size.
Next, I set my docker systemd service file to startup with the desired container size. This is required so that the docker service will start the containers up with the desired size. I edited the OPTIONS variable in the /etc/sysconfig/docker file. It now looks like this:
OPTIONS='--selinux-enabled --storage-opt dm.basesize=13G'
Finally, restart the docker service:
sudo service stop docker
References
[1] https://jpetazzo.github.io/2014/01/29/docker-device-mapper-resize/ - This is how I discovered RedHat uses device-mapper, and that device-mapper has a 10G limit.
[2] https://docs.docker.com/reference/commandline/cli/ - Found the storage options in dockers documentation.

Resources