Bug#1050993: podman: Podman should use overlay storage driver by default instead of vfs

[Gregor Riepl]

Package: podman
Version: 4.4.0+ds1-1
Severity: normal
Forwarded: https://github.com/containers/podman/issues/19811
X-Debbugs-Cc: oni...@gmail.com

The vfs storage driver in Podman has been the recommended upstream default up
until 4.4, but there isn't really a good reason to use it any more. The overlay
driver is faster and more conservative in most cases.

Please upgrade Podman to 4.5+ (4.6.3 is current) in Debian, or add the
configuration file /etc/containers/storage.conf with the following contents:

[storage]
driver = "overlay"

For reference, I ran into a serious storage explosion with the vfs driver
recently: https://github.com/containers/podman/issues/19811
This issue doesn't occur with the overlay driver.

Thanks!


-- System Information:
Debian Release: trixie/sid
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'unstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 6.4.0-2-amd64 (SMP w/16 CPU threads; PREEMPT)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages podman depends on:
ii conmon 2.1.6+ds1-1
ii golang-github-containers-common 0.50.1+ds1-4
ii libc6 2.37-7
ii libdevmapper1.02.1 2:1.02.185-2
ii libgpgme11 1.18.0-3+b1
ii libseccomp2 2.5.4-1+b3
ii libsubid4 1:4.13+dfsg1-1+b1
ii runc 1.1.5+ds1-1+b2

Versions of packages podman recommends:
ii buildah 1.29.0+ds1-1
ii dbus-user-session 1.14.8-2
ii fuse-overlayfs 1.10-1
ii slirp4netns 1.2.0-1
ii tini 0.19.0-1
ii uidmap 1:4.13+dfsg1-1+b1

Versions of packages podman suggests:
pn containers-storage <none>
pn docker-compose <none>
ii iptables 1.8.9-2

-- Configuration Files:
/etc/cni/net.d/87-podman-bridge.conflist [Errno 13] Permission denied: '/etc/cni/net.d/87-podman-bridge.conflist'

-- no debconf information

[Gregor Riepl]

Package: podman
Version: 4.5.1+ds1-2
Followup-For: Bug #1050993
X-Debbugs-Cc: oni...@gmail.com
Control: found -1

Thanks for upgrading the package, but it looks like the issue isn't fixed in
4.5 after all.

After upgrading and removing /etc/containers/storage.conf (to revert to default
behavior), I'm now facing the following error:

ERRO[0000] User-selected graph driver "vfs" overwritten by graph driver
"overlay" from database - delete libpod local files
("/home/user/.local/share/containers/storage") to resolve. May prevent use of
images created by other tools

This indicates that the vfs driver was autoselected, despite overlay being
available.

In fact, if I explicitly run podman with the option "--storage-driver overlay",
it works fine.

-- System Information:
Debian Release: trixie/sid
APT prefers testing
APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'unstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 6.4.0-4-amd64 (SMP w/16 CPU threads; PREEMPT)

Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages podman depends on:
ii conmon 2.1.6+ds1-1
ii golang-github-containers-common 0.50.1+ds1-4
ii libc6 2.37-7
ii libdevmapper1.02.1 2:1.02.185-2
ii libgpgme11 1.18.0-3+b1
ii libseccomp2 2.5.4-1+b3

ii libsqlite3-0 3.43.0-1

ii libsubid4 1:4.13+dfsg1-1+b1
ii runc 1.1.5+ds1-1+b2

Versions of packages podman recommends:

ii buildah 1.30.0+ds1-3
ii dbus-user-session 1.14.10-1

ii slirp4netns 1.2.0-1
ii tini 0.19.0-1
ii uidmap 1:4.13+dfsg1-1+b1

Versions of packages podman suggests:
pn containers-storage <none>
pn docker-compose <none>

ii fuse-overlayfs 1.10-1

[Reinhard Tartler]

Hi Gregor,

On Wed, Sep 13, 2023 at 3:03 AM Gregor Riepl <oni...@gmail.com> wrote:

As mentioned in the upstream bug report[1], the fix is actually in
containers/storage 1.48, included with podman 4.6 and not 4.5.

So, the bug can (hopefully) be fixed for good when this version is packaged.

I've now worked on packaging 4.6.2, and it is currently available

in debian/experimental. Can you do me a favor? Please test it and let me know whether

it fixes this issue.

It might also be helpful to include a what's new message, to make users
aware they need to reset their storage after upgrading. There doesn't
seem to be an easy way to convert vfs containers or images to overlay.

[1]
https://github.com/containers/podman/issues/19811#issuecomment-1716344802

I'm happy to add a note in NEWS.Debian, which is going to be presented

on package upgrades. Can you please provide a wording for that text that you

would have been useful to you?

Thank you 

--

regards,
    Reinhard