Sharing a dir with container problem

Im running incus on ubuntu 24.04 and im trying to make a shared dir with the container.

Two things were suggested: shift:true and idmap, both of which i have problems with.

add device

incus config device add container container-data disk source=/data/storage/data/container/ path=/data/container

try shiftfs

incus config device container container-data set shift=true

results in an error

Error: Failed to start device "container-data": The "shift" property cannot be used with a restricted source path

try idmap

incus config set container raw.idmap="uid 1000 103"
incus restart container

results in an error

Error: Failed to run: /usr/libexec/incus/incusd forkstart user-1000_container /var/lib/incus/containers /run/incus/user-1000_container/lxc.conf: exit status 1
Try `incus info --show-log container` for more info

Name: container
Status: STOPPED
Type: container
Architecture: x86_64
Created: 2024/07/07 15:17 UTC
Last Used: 2024/07/07 15:35 UTC

Log:

lxc user-1000_container 20240707153533.823 ERROR    conf - ../src/lxc/conf.c:lxc_map_ids:3704 - newuidmap failed to write mapping "newuidmap: uid range [103-104) -> [1000-1001) not allowed": newuidmap 8201 0 1000000 103 103 1000 1 104 1000104 999999896
lxc user-1000_container 20240707153533.823 ERROR    start - ../src/lxc/start.c:lxc_spawn:1788 - Failed to set up id mapping.
lxc user-1000_container 20240707153533.823 ERROR    lxccontainer - ../src/lxc/lxccontainer.c:wait_on_daemonized_start:878 - Received container state "ABORTING" instead of "RUNNING"
lxc user-1000_container 20240707153533.827 ERROR    start - ../src/lxc/start.c:__lxc_start:2107 - Failed to spawn container "user-1000_container"
lxc user-1000_container 20240707153533.827 WARN     start - ../src/lxc/start.c:lxc_abort:1036 - No such process - Failed to send SIGKILL via pidfd 17 for process 8201
lxc 20240707153533.884 ERROR    af_unix - ../src/lxc/af_unix.c:lxc_abstract_unix_recv_fds_iov:218 - Connection reset by peer - Failed to receive response
lxc 20240707153533.884 ERROR    commands - ../src/lxc/commands.c:lxc_cmd_rsp_recv_fds:128 - Failed to receive file descriptors for command "get_init_pid"

project config

config:
  features.images: "true"
  features.networks: "false"
  features.networks.zones: "true"
  features.profiles: "true"
  features.storage.buckets: "true"
  features.storage.volumes: "true"
  restricted: "true"
  restricted.containers.nesting: allow
  restricted.devices.disk: allow
  restricted.devices.disk.paths: /home/user,/data/storage
  restricted.devices.gpu: allow
  restricted.idmap.gid: "1000"
  restricted.idmap.uid: "1000"
  restricted.networks.access: incusbr-1000

how can i make a user with uid 1000 on host have some specific uid within the container? i.e. the process within the container, when writing files, should from the host look like it is using uid 1000.

One thing to note: I’m trying to do this as a normal user, not root.

what was needed is to add

root:1000:1

to /etc/subgid and /etc/subuid to make raw.idmap work