Manage data volume in Docker container

Possible way to keep data in container:

1. Storing data within the container
2. Store your data outside Docker’s Union Filesystem
3. Mounting a volume within the Docker host’s filesystem
4. Storing data on a network-attached block device. Docker volume plugins allow you to provision and mount shared storage, such as iSCSI, NFS, or FC

Case 1: It 's normal case, you can store any data to guest OS file system. When run container and show your filesystem with 'df' command, show you like this

docker@default:~$
docker@default:~$ docker run -it --name oel-guest1 --rm oraclelinux:7.2 bash
[root@acbc5894fa52 /]#
[root@acbc5894fa52 /]#
[root@acbc5894fa52 /]# df -m
Filesystem     1M-blocks  Used Available Use% Mounted on
none               18306  1808     15532  11% /
tmpfs                498     0       498   0% /dev
tmpfs                498     0       498   0% /sys/fs/cgroup
/dev/sda1          18306  1808     15532  11% /etc/hosts
shm                   64     0        64   0% /dev/shm
[root@acbc5894fa52 /]#

Case  2: Create or run container as volume container. This volume container can share among containers in same Docker host

docker create -v /orahome --name orahome oraclelinux:7.2 /bin/true

docker run -it --volumes-from orahome --name db1 oraclelinux:7.2 bash
[root@b5c9355faefb /]#
[root@b5c9355faefb /]# df -k
Filesystem     1K-blocks    Used Available Use% Mounted on
none            18745336 1850824  15903788  11% /
tmpfs             509888       0    509888   0% /dev
tmpfs             509888       0    509888   0% /sys/fs/cgroup
/dev/sda1       18745336 1850824  15903788  11% /orahome
shm                65536       0     65536   0% /dev/shm

exit
docker inspect db1

...
 "Mounts": [
            {
                "Name": "8b552ab768be1f3d7ddc73059dbab62d82a0c316fc7c5303e6833377fcbdb937",
                "Source": "/mnt/sda1/var/lib/docker/volumes/8b552ab768be1f3d7ddc73059dbab62d82a0c316fc7c5303e6833377fcbdb937/_data",
                "Destination": "/orahome",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            }
        ],

...

Mount multiple volume

docker create -v /oradata --name oradata oraclelinux:7.2 /bin/true

docker run -it --rm  --volumes-from=oradata --volumes-from=orahome --name db1 oraclelinux:7.2 bash

-- add host share folder
docker run -it --rm --privileged -v /cygdrive/d/TEMP:/test --volumes-from=oradata --volumes-from=orahome --name db1 oraclelinux:7.2 bash

docker inspect db1

"Mounts": [
            {
                "Name": "1def11f59155cd3e02bb2b1f94dbe84e0c3b8aff6834e3146da1f21d9ce25c70",
                "Source": "/mnt/sda1/var/lib/docker/volumes/1def11f59155cd3e02bb2b1f94dbe84e0c3b8aff6834e3146da1f21d9ce25c70/_data",
                "Destination": "/oradata",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Name": "8b552ab768be1f3d7ddc73059dbab62d82a0c316fc7c5303e6833377fcbdb937",
                "Source": "/mnt/sda1/var/lib/docker/volumes/8b552ab768be1f3d7ddc73059dbab62d82a0c316fc7c5303e6833377fcbdb937/_data",
                "Destination": "/orahome",
                "Driver": "local",
                "Mode": "",
                "RW": true,
                "Propagation": ""
            },
            {
                "Source": "/cygdrive/d/TEMP",
                "Destination": "/test",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            }
        ],

Case 3: Mounting host file system (Boot2Docker linux)

docker@default:~$ docker run -it --name hostdir --privileged -v /cygdrive/d/TEMP:/test oraclelinux:7.2 bash
[root@ea3d6181c614 /]# df -k
Filesystem     1K-blocks      Used Available Use% Mounted on
none            18745336   1355072  16399540   8% /
tmpfs             509888         0    509888   0% /dev
tmpfs             509888         0    509888   0% /sys/fs/cgroup
temp           439887868 211736176 228151692  49% /test
/dev/sda1       18745336   1355072  16399540   8% /etc/hosts
shm                65536         0     65536   0% /dev/shm
[root@ea3d6181c614 /]# exit
exit
docker@default:~$ docker inspect hostdir

...

 "Mounts": [
            {
                "Source": "/cygdrive/d/TEMP",
                "Destination": "/test",
                "Mode": "",
                "RW": true,
                "Propagation": "rprivate"
            }
        ],

...

Case 4: Use Docker volume plugin

..... coming soon .....