Fedora 40
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Podman : Use External Storage2024/05/03

 
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.
[1] It's possible to mount a directory on Podman 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@27d1acb64b11 /]#
df -hT /mnt

Filesystem              Type  Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root xfs    78G  3.9G   75G   5% /mnt

[root@27d1acb64b11 /]#
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": "2024-05-03T15:49:54.689374127+09:00",
          "Labels": {},
          "Scope": "local",
          "Options": {},
          "MountCount": 0,
          "NeedsCopyUp": true,
          "NeedsChown": true,
          "LockNumber": 8
     }
]

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

[root@dlp ~]#
podman run -it -v volume01:/mnt fedora
[root@65acfb302856 /]#
df -hT /mnt

Filesystem              Type  Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root xfs    78G  3.9G   75G   5% /mnt

[root@65acfb302856 /]#
echo "Podman Volume test" > /mnt/testfile.txt

[root@65acfb302856 /]#
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): 65acfb30285667272ab73109cb7fa9b78076c7048852e14282737dcf5debce40, 3dac45d20b43ae4e352b508800fb0a53b43a125755eba07fe0460c48ff458518: 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 65acfb30285667272ab73109cb7fa9b78076c7048852e14282737dcf5debce40

[root@dlp ~]#
podman rm 3dac45d20b43ae4e352b508800fb0a53b43a125755eba07fe0460c48ff458518
[root@dlp ~]#
podman volume rm volume01

volume01
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