Containers in Proxmox VE

Containers in Proxmox VE

It should be easy but there are few quirks.

First you need to get suitable "Template" (tarball with container content) as describe on:

• https://pve.proxmox.com/wiki/Linux_Container

For example:

pveam update
pveam available --section system
pveam download debian-11-standard_11.3-1_amd64.tar.zst
pveam download local debian-11-standard_11.3-1_amd64.tar.zst
pveam list local

Next you have to enable content type rootdir so it will be offered as storage. In my case I simply did this:

pvesm status
cat /etc/pve/storage.cfg 
# ensure that you do NOT remove any existing content type:
pvesm set local --content iso,vztmpl,backup,rootdir,images
cat /etc/pve/storage.cfg 

Using dir storage "chroot"

Normally recent Proxmox allows you to use only Volumes (images formatted with filesystem) from GUI, as pointed out on:

• https://forum.proxmox.com/threads/pct-create-size-0-on-gui.42217/

Creating subdir storage is possible from CLI only, for example:

pct create 402 /var/lib/vz/template/cache/debian-11-standard_11.3-1_amd64.tar.zst \
    --hostname deb11-ct --rootfs local:0 --password SecurePassword

You can verify that VM filesystem is real subdirectory using command like this:

ls -l /var/lib/vz/images/402/subvol-402-disk-0.subvol/

Gentoo note

I was curious and tried container with Gentoo using

pveam download local gentoo-current-openrc_20231009_amd64.tar.xz
pct create 224 /var/lib/vz/template/cache/gentoo-current-openrc_20231009_amd64.tar.xz \
 --hostname gentoo-ct --rootfs local:0 --password TopSecretPassword

But when I tried emerge any package (in my case emerge-webrsync && emerge -an tmux, got:

mount: /proc: cannot mount none read-only.
       dmesg(1) may have more information after failed mount system call.
Unable to mark /proc slave: 32
 * The ebuild phase 'die_hooks' has been aborted since PORTAGE_BUILDDIR
 * does not exist: '/var/tmp/portage/dev-libs/libevent-2.1.12-r1'

There exist two workarounds:

Workaround A:

• https://forums.gentoo.org/viewtopic-t-1095098-start-0.html
• disable pid-sandbox feature:
• add to /etc/portage/make.conf

  FEATURES="-pid-sandbox"

  It is likely less secure.

Workaround B:

• https://forum.proxmox.com/threads/gentoo-lxc-image-does-not-have-correct-features.77891/
• allow container nesting:

pct set CONTAINER_ID --features nesting=1

And "power cycle" container (shutdown and start again).