Fedora 35
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Podman : Use External Storage2021/11/11

 
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]

# if SELinux is [Enforcing], it needs to add [--privileged] option

[root@dlp ~]#
podman run --privileged -it -v /var/lib/containers/disk01:/mnt fedora /bin/bash
[root@f8112341df43 /]#
df -hT /mnt

Filesystem                     Type  Size  Used Avail Use% Mounted on
/dev/mapper/fedora_fedora-root xfs    78G  3.0G   75G   4% /mnt

[root@f8112341df43 /]#
cat /mnt/testfile.txt

persistent storage
[2] It's also possible to configure external storage by Docker 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": "2021-11-11T09:25:29.587655921+09:00",
        "Labels": {},
        "Scope": "local",
        "Options": {}
    }
]

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

[root@dlp ~]#
podman run -it -v volume01:/mnt fedora
[root@ee063d26b00f /]#
df -hT /mnt

Filesystem                     Type  Size  Used Avail Use% Mounted on
/dev/mapper/fedora_fedora-root xfs    78G  3.0G   75G   4% /mnt

[root@ee063d26b00f /]#
echo "Podman Volume test" > /mnt/testfile.txt

[root@ee063d26b00f /]#
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 fedora /usr/bin/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): dbdafa671c20dc33195922a9301ae94783d90991001a97b050505eb8d46a7775, ee063d26b00f5d1eb2f977c9243edf17d54b8f1b428cba06b5e7cc205afb547e: 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 dbdafa671c20dc33195922a9301ae94783d90991001a97b050505eb8d46a7775

[root@dlp ~]#
podman rm ee063d26b00f5d1eb2f977c9243edf17d54b8f1b428cba06b5e7cc205afb547e
[root@dlp ~]#
podman volume rm volume01

volume01
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