Podman : Use External Storage2022/04/28

	When a Container is removed, data in it are also lost, so it's necessary to use external storage on Containers if you'd like to save your data on Containers.
[1]	It's possible to mount a directory on Docker Host into Containers.

# create a directory for containers data

root@dlp:~#

mkdir /var/lib/containers/disk01

root@dlp:~#

echo "persistent storage" >> /var/lib/containers/disk01/testfile.txt

# run a Container with mounting the directory above on [/mnt]

root@dlp:~#

podman run -it -v /var/lib/containers/disk01:/mnt ubuntu /bin/bash

root@6b6bda792ea3:/#

df -hT /mnt

Filesystem                        Type  Size  Used Avail Use% Mounted on
/dev/mapper/ubuntu--vg-ubuntu--lv ext4   77G  7.8G   65G  11% /mnt

root@6b6bda792ea3:/#

cat /mnt/testfile.txt

persistent storage

[2]	It's also possible to configure external storage by Podman Data Volume command.

# create [volume01] volume

root@dlp:~#

podman volume create volume01

volume01

# display volume list

root@dlp:~#

podman volume ls

DRIVER      VOLUME NAME
local       volume01

# display details of [volume01]

root@dlp:~#

podman volume inspect volume01

[
    {
        "Name": "volume01",
        "Driver": "local",
        "Mountpoint": "/var/lib/containers/storage/volumes/volume01/_data",
        "CreatedAt": "2022-04-28T05:42:08.22607491Z",
        "Labels": {},
        "Scope": "local",
        "Options": {}
    }
]

# run a container with mounting [volume01] to [/mnt] on container

root@dlp:~#

podman run -it -v volume01:/mnt ubuntu

root@c672d2c1d60c:/#

df -hT /mnt

Filesystem                        Type  Size  Used Avail Use% Mounted on
/dev/mapper/ubuntu--vg-ubuntu--lv ext4   77G  7.8G   65G  11% /mnt

root@c672d2c1d60c:/#

echo "Podman Volume test" > /mnt/testfile.txt

root@c672d2c1d60c:/#

exit

root@dlp:~#

cat /var/lib/containers/storage/volumes/volume01/_data/testfile.txt

Podman Volume test

# possible to mount from other containers

root@dlp:~#

podman run -v volume01:/var/volume01 ubuntu cat /var/volume01/testfile.txt

Podman Volume test

# to remove volumes, do like follows

root@dlp:~#

podman volume rm volume01

Error: volume volume01 is being used by the following container(s): 633611bf03f40daa6fde23a7d93aea6dbc715b23cde661f1f1100ddbd140f67b, c672d2c1d60c351926f5739ea0f87fd49b809e1c6fd64820deb766e67e68e5bc: volume is being used

# if some containers are using the volume you'd like to remove like above,
# it needs to remove target containers before removing a volume

root@dlp:~#

podman rm 633611bf03f40daa6fde23a7d93aea6dbc715b23cde661f1f1100ddbd140f67b

root@dlp:~#

podman rm c672d2c1d60c351926f5739ea0f87fd49b809e1c6fd64820deb766e67e68e5bc

root@dlp:~#

podman volume rm volume01

volume01

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