Comment by kgxohxkhclhc

docker and podman expect to extract images to disk, then use fancy features like overlayfs, which doesn't work on network filesystems -- and in hpc, most filesystems users can write to persistently are network filesystems.

apptainer images are straight filesystem images with no overlayfs or storage driver magic happening -- just a straight loop mount of a disk image.

this means your container images can now live on your network filesystem.