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Podman : Use External Storage2021/08/28

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

root@dlp:~#
podman run -it -v /var/lib/containers/disk01:/mnt debian /bin/bash
root@6dc5d9629e9d:/#
df -hT /mnt

Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/debian--vg-root ext4   77G  1.7G   72G   3% /mnt

root@6dc5d9629e9d:/#
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": "2021-08-27T03:25:59.627987896-05:00",
        "Labels": {},
        "Scope": "local",
        "Options": {}
    }
]

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

root@dlp:~#
podman run -it -v volume01:/mnt debian
root@2422e000e0ab:/#
df -hT /mnt

Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/debian--vg-root ext4   77G  1.7G   72G   3% /mnt

root@2422e000e0ab:/#
echo "Podman Volume test" > /mnt/testfile.txt

root@2422e000e0ab:/#
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 debian 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): 2422e000e0abef3611ec3d0306b5454cbccdd43d77aaf9534ce41a14d1572755, 2a3969da9f51370c78e7753d35f094ff4ec23e79196ad198fe7888087b950240: 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 2422e000e0abef3611ec3d0306b5454cbccdd43d77aaf9534ce41a14d1572755

root@dlp:~#
podman rm 2a3969da9f51370c78e7753d35f094ff4ec23e79196ad198fe7888087b950240
root@dlp:~#
podman volume rm volume01

volume01
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