Necrobumping this thread as Iβm having the same issue in the same scenario (attempting to run a podman container inside a NixOS guest running in an LXD container).
Iβve had the same results as the OP to this point.
findmnt
on host
TARGET SOURCE FSTYPE OPTIONS
/ /dev/loop0 squashfs ro,relatime
ββ/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
β ββ/sys/kernel/security securityfs securityfs rw,nosuid,nodev,noexec,relatime
β ββ/sys/fs/cgroup tmpfs tmpfs ro,nosuid,nodev,noexec,mode=755
β β ββ/sys/fs/cgroup/unified cgroup2 cgroup2 rw,nosuid,nodev,noexec,relatime
β β ββ/sys/fs/cgroup/systemd cgroup cgroup rw,nosuid,nodev,noexec,relatime,xattr,name=systemd
β β ββ/sys/fs/cgroup/net_cls,net_prio cgroup cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio
β β ββ/sys/fs/cgroup/freezer cgroup cgroup rw,nosuid,nodev,noexec,relatime,freezer
β β ββ/sys/fs/cgroup/blkio cgroup cgroup rw,nosuid,nodev,noexec,relatime,blkio
β β ββ/sys/fs/cgroup/cpu,cpuacct cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct
β β ββ/sys/fs/cgroup/rdma cgroup cgroup rw,nosuid,nodev,noexec,relatime,rdma
β β ββ/sys/fs/cgroup/perf_event cgroup cgroup rw,nosuid,nodev,noexec,relatime,perf_event
β β ββ/sys/fs/cgroup/hugetlb cgroup cgroup rw,nosuid,nodev,noexec,relatime,hugetlb
β β ββ/sys/fs/cgroup/memory cgroup cgroup rw,nosuid,nodev,noexec,relatime,memory
β β ββ/sys/fs/cgroup/devices cgroup cgroup rw,nosuid,nodev,noexec,relatime,devices
β β ββ/sys/fs/cgroup/pids cgroup cgroup rw,nosuid,nodev,noexec,relatime,pids
β β ββ/sys/fs/cgroup/cpuset cgroup cgroup rw,nosuid,nodev,noexec,relatime,cpuset,clone_children
β ββ/sys/fs/pstore pstore pstore rw,nosuid,nodev,noexec,relatime
β ββ/sys/firmware/efi/efivars efivarfs efivarfs rw,nosuid,nodev,noexec,relatime
β ββ/sys/fs/bpf none bpf rw,nosuid,nodev,noexec,relatime,mode=700
β ββ/sys/kernel/debug debugfs debugfs rw,nosuid,nodev,noexec,relatime
β ββ/sys/kernel/tracing tracefs tracefs rw,nosuid,nodev,noexec,relatime
β ββ/sys/fs/fuse/connections fusectl fusectl rw,nosuid,nodev,noexec,relatime
β ββ/sys/kernel/config configfs configfs rw,nosuid,nodev,noexec,relatime
ββ/proc proc proc rw,nosuid,nodev,noexec,relatime
β ββ/proc/sys/fs/binfmt_misc systemd-1 autofs rw,relatime,fd=29,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=15249
β ββ/proc/sys/fs/binfmt_misc binfmt_misc binfmt_misc rw,nosuid,nodev,noexec,relatime
ββ/dev devtmpfs devtmpfs rw,nosuid,size=3972152k,nr_inodes=993038,mode=755
β ββ/dev/shm tmpfs tmpfs rw,nosuid,nodev
β ββ/dev/pts devpts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000
β ββ/dev/hugepages hugetlbfs hugetlbfs rw,relatime,pagesize=2M
β ββ/dev/mqueue mqueue mqueue rw,nosuid,nodev,noexec,relatime
ββ/run tmpfs tmpfs rw,nosuid,nodev,size=797816k,mode=755
β ββ/run/lock tmpfs tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k
β ββ/run/mnt/ubuntu-boot /dev/nvme0n1p3 ext4 rw,relatime
β ββ/run/mnt/ubuntu-seed /dev/nvme0n1p2 vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
β ββ/run/mnt/data /dev/nvme0n1p5 ext4 rw,nosuid,relatime
β ββ/run/mnt/ubuntu-save /dev/nvme0n1p4 ext4 rw,relatime
β ββ/run/mnt/base /dev/loop0 squashfs ro,relatime
β ββ/run/mnt/kernel /dev/loop1 squashfs ro,relatime
β ββ/run/snapd/ns tmpfs[/snapd/ns] tmpfs rw,nosuid,nodev,size=797816k,mode=755
β β ββ/run/snapd/ns/lxd.mnt nsfs[mnt:[4026532813]] nsfs rw
β ββ/run/user/1000 tmpfs tmpfs rw,nosuid,nodev,relatime,size=797812k,mode=700,uid=1000,gid=1000
ββ/boot/efi /dev/nvme0n1p2 vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
ββ/boot/grub /dev/nvme0n1p3[/EFI/ubuntu] ext4 rw,relatime
ββ/media tmpfs tmpfs rw,relatime
ββ/mnt tmpfs tmpfs rw,relatime
ββ/home /dev/nvme0n1p5[/user-data] ext4 rw,nosuid,relatime
ββ/host tmpfs[/mnt/host] tmpfs rw,nosuid,nodev,size=797816k,mode=755
ββ/root /dev/nvme0n1p5[/system-data/root] ext4 rw,nosuid,relatime
ββ/tmp tmpfs tmpfs rw,relatime
ββ/snap /dev/nvme0n1p5[/system-data/snap] ext4 rw,nosuid,relatime
β ββ/snap/pc-kernel/1238 /dev/loop1 squashfs ro,nodev,relatime
β ββ/snap/core/14784 /dev/loop3 squashfs ro,nodev,relatime
β ββ/snap/core/14447 /dev/loop2 squashfs ro,nodev,relatime
β ββ/snap/core20/1822 /dev/loop5 squashfs ro,nodev,relatime
β ββ/snap/core/14946 /dev/loop6 squashfs ro,nodev,relatime
β ββ/snap/core20/1852 /dev/loop0 squashfs ro,nodev,relatime
β ββ/snap/core18/2708 /dev/loop7 squashfs ro,nodev,relatime
β ββ/snap/lxd/24483 /dev/loop9 squashfs ro,nodev,relatime
β ββ/snap/core20/1828 /dev/loop8 squashfs ro,nodev,relatime
β ββ/snap/snapd/18357 /dev/loop10 squashfs ro,nodev,relatime
β ββ/snap/pc/132 /dev/loop12 squashfs ro,nodev,relatime
β ββ/snap/pc-kernel/1229 /dev/loop11 squashfs ro,nodev,relatime
β ββ/snap/lxd/24323 /dev/loop13 squashfs ro,nodev,relatime
β ββ/snap/pc/115 /dev/loop14 squashfs ro,nodev,relatime
β ββ/snap/core22/583 /dev/loop22 squashfs ro,nodev,relatime
β ββ/snap/snapd/18596 /dev/loop15 squashfs ro,nodev,relatime
β ββ/snap/snapd/17950 /dev/loop17 squashfs ro,nodev,relatime
β ββ/snap/lxd/24643 /dev/loop16 squashfs ro,nodev,relatime
β ββ/snap/core22/547 /dev/loop18 squashfs ro,nodev,relatime
β ββ/snap/pc-kernel/1198 /dev/loop19 squashfs ro,nodev,relatime
β ββ/snap/core18/2714 /dev/loop20 squashfs ro,nodev,relatime
β ββ/snap/core18/2721 /dev/loop23 squashfs ro,nodev,relatime
ββ/var/cache/apparmor /dev/nvme0n1p5[/system-data/var/cache/apparmor] ext4 rw,nosuid,relatime
ββ/var/lib/cloud /dev/nvme0n1p5[/system-data/var/lib/cloud] ext4 rw,nosuid,relatime
ββ/var/lib/console-conf /dev/nvme0n1p5[/system-data/var/lib/console-conf] ext4 rw,nosuid,relatime
ββ/var/cache/snapd /dev/nvme0n1p5[/system-data/var/cache/snapd] ext4 rw,nosuid,relatime
ββ/var/lib/dhcp /dev/nvme0n1p5[/system-data/var/lib/dhcp] ext4 rw,nosuid,relatime
ββ/var/lib/dbus /dev/nvme0n1p5[/system-data/var/lib/dbus] ext4 rw,nosuid,relatime
ββ/var/lib/extrausers /dev/nvme0n1p5[/system-data/var/lib/extrausers] ext4 rw,nosuid,relatime
ββ/var/lib/misc /dev/nvme0n1p5[/system-data/var/lib/misc] ext4 rw,nosuid,relatime
ββ/var/lib/private/systemd /dev/nvme0n1p5[/system-data/var/lib/private/systemd] ext4 rw,nosuid,relatime
ββ/var/lib/snapd /dev/nvme0n1p5[/system-data/var/lib/snapd] ext4 rw,nosuid,relatime
β ββ/var/lib/snapd/save /dev/nvme0n1p4 ext4 rw,relatime
β ββ/var/lib/snapd/seed /dev/nvme0n1p2 vfat ro,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
ββ/var/lib/systemd /dev/nvme0n1p5[/system-data/var/lib/systemd] ext4 rw,nosuid,relatime
ββ/var/log /dev/nvme0n1p5[/system-data/var/log] ext4 rw,nosuid,relatime
ββ/var/lib/sudo tmpfs tmpfs rw,relatime,mode=700
ββ/var/snap /dev/nvme0n1p5[/system-data/var/snap] ext4 rw,nosuid,relatime
β ββ/var/snap/lxd/common/ns tmpfs tmpfs rw,relatime,size=1024k,mode=700
β ββ/var/snap/lxd/common/ns/mntns nsfs[mnt:[4026532341]] nsfs rw
β ββ/var/snap/lxd/common/ns/shmounts nsfs[mnt:[4026532546]] nsfs rw
ββ/writable /dev/nvme0n1p5 ext4 rw,nosuid,relatime
β ββ/writable/system-data/snap/pc-kernel/1238 /dev/loop1 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core/14784 /dev/loop3 squashfs ro,nodev,relatime
β ββ/writable/system-data/var/lib/snapd/save /dev/nvme0n1p4 ext4 rw,relatime
β ββ/writable/system-data/var/lib/snapd/seed /dev/nvme0n1p2 vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
β ββ/writable/system-data/snap/core/14447 /dev/loop2 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core20/1822 /dev/loop5 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core/14946 /dev/loop6 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core20/1852 /dev/loop0 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core18/2708 /dev/loop7 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/lxd/24483 /dev/loop9 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core20/1828 /dev/loop8 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/snapd/18357 /dev/loop10 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/pc/132 /dev/loop12 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/pc-kernel/1229 /dev/loop11 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/lxd/24323 /dev/loop13 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core22/583 /dev/loop22 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/snapd/18596 /dev/loop15 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/pc/115 /dev/loop14 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/snapd/17950 /dev/loop17 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/lxd/24643 /dev/loop16 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core22/547 /dev/loop18 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/pc-kernel/1198 /dev/loop19 squashfs ro,nodev,relatime
β ββ/writable/system-data/snap/core18/2714 /dev/loop20 squashfs ro,nodev,relatime
β ββ/writable/system-data/var/snap/lxd/common/ns tmpfs tmpfs rw,relatime,size=1024k,mode=700
β ββ/writable/system-data/snap/core18/2721 /dev/loop23 squashfs ro,nodev,relatime
ββ/usr/lib/firmware /dev/loop1[/firmware] squashfs ro,relatime
ββ/etc/fstab tmpfs[/image.fstab] tmpfs rw,nosuid,nodev,size=797816k,mode=755
ββ/etc/writable /dev/nvme0n1p5[/system-data/etc/writable] ext4 rw,nosuid,relatime
ββ/etc/dbus-1 /dev/nvme0n1p5[/system-data/etc/dbus-1] ext4 rw,nosuid,relatime
ββ/etc/hosts /dev/nvme0n1p5[/system-data/etc/hosts] ext4 rw,nosuid,relatime
ββ/etc/iproute2 /dev/nvme0n1p5[/system-data/etc/iproute2] ext4 rw,nosuid,relatime
ββ/etc/modprobe.d /dev/nvme0n1p5[/system-data/etc/modprobe.d] ext4 rw,nosuid,relatime
ββ/etc/modules-load.d /dev/nvme0n1p5[/system-data/etc/modules-load.d] ext4 rw,nosuid,relatime
ββ/etc/netplan /dev/nvme0n1p5[/system-data/etc/netplan] ext4 rw,nosuid,relatime
ββ/etc/network/if-up.d /dev/nvme0n1p5[/system-data/etc/network/if-up.d] ext4 rw,nosuid,relatime
ββ/etc/ssh /dev/nvme0n1p5[/system-data/etc/ssh] ext4 rw,nosuid,relatime
ββ/etc/sudoers.d /dev/nvme0n1p5[/system-data/etc/sudoers.d] ext4 rw,nosuid,relatime
ββ/etc/systemd /dev/nvme0n1p5[/system-data/etc/systemd] ext4 rw,nosuid,relatime
ββ/etc/udev/rules.d /dev/nvme0n1p5[/system-data/etc/udev/rules.d] ext4 rw,nosuid,relatime
ββ/etc/cloud /dev/nvme0n1p5[/system-data/etc/cloud] ext4 rw,nosuid,relatime
ββ/etc/sysctl.d /dev/nvme0n1p5[/system-data/etc/sysctl.d] ext4 rw,nosuid,relatime
ββ/etc/default/swapfile /dev/nvme0n1p5[/system-data/etc/default/swapfile] ext4 rw,nosuid,relatime
ββ/etc/environment /dev/nvme0n1p5[/system-data/etc/environment] ext4 rw,nosuid,relatime
ββ/etc/machine-id /dev/nvme0n1p5[/system-data/etc/machine-id] ext4 rw,nosuid,relatime
ββ/etc/update-motd.d /dev/nvme0n1p5[/system-data/etc/update-motd.d] ext4 rw,nosuid,relatime
ββ/etc/security/pwquality.conf /dev/nvme0n1p5[/system-data/etc/security/pwquality.conf] ext4 rw,nosuid,relatime
ββ/usr/lib/modules /dev/loop1[/modules] squashfs ro,relatime
ββ/var/tmp /dev/nvme0n1p5[/system-data/var/tmp] ext4 rw,nosuid,relatime
ββ/usr/lib/snapd /dev/loop15[/usr/lib/snapd] squashfs ro,nodev,relatime
cat /proc/<container-init-pid>/cgroup
12:cpuset:/lxc.payload.nix-btrfs
11:pids:/lxc.payload.nix-btrfs
10:devices:/lxc.payload.nix-btrfs
9:memory:/lxc.payload.nix-btrfs
8:hugetlb:/lxc.payload.nix-btrfs
7:perf_event:/lxc.payload.nix-btrfs
6:rdma:/lxc.payload.nix-btrfs
5:cpu,cpuacct:/lxc.payload.nix-btrfs
4:blkio:/lxc.payload.nix-btrfs
3:freezer:/lxc.payload.nix-btrfs
2:net_cls,net_prio:/lxc.payload.nix-btrfs
1:name=systemd:/lxc.payload.nix-btrfs
0::/lxc.payload.nix-btrfs/init.scope