Enter the UIDs and GIDs you want to pass through from the host into your LXC container. The tool generates the lxc.idmap block for your container config, the /etc/subuid and /etc/subgid entries needed on the Proxmox host.
Privileged containers share host UIDs/GIDs directly — no lxc.idmap or subuid changes are needed. Only a host chown is required.
/etc/pve/lxc/<CTID>.conf
Enter a CTID and UID(s) to generate idmap lines./etc/subuid + /etc/subgid
Enter a CTID and UID(s) to generate subuid/subgid lines.Finding IDs on the Proxmox Host
Run these commands in a Proxmox host shell to find the UID and GID you need:
# Your current user
id
# A specific service user (e.g. jellyfin, www-data)
id jellyfin
# Look up a user by name in the full user database
getent passwd jellyfin
The output looks like uid=1000(jellyfin) gid=1000(jellyfin) groups=.... The number after uid= is the UID; the number after gid= is the primary GID. Enter those numbers into the tool above.
Finding IDs inside the LXC Container
Run these commands from the Proxmox host to query IDs inside a running container (replace 101 with your CTID):
# Look up a user inside the container
pct exec 101 -- id jellyfin
# Check what uid_map the container is using
pct exec 101 -- cat /proc/self/uid_map
# Or enter the container shell directly
pct enter 101
id jellyfin
The id output inside the container shows the LXC-side IDs — these are what go into the lxc.idmap lines. The Proxmox host sees the mapped host IDs instead.
For the conceptual background on how UID/GID mapping works, the default offset layout, and common bind-mount troubleshooting.