how can i separate container overlay and image overlay dir in rootless mode?

[lddlww]

i wanna to limit rootfs size for a container in rootless mode using lvm and build new image ，however for large modify within container ， build image always failed as no space left on device

step 1: create lvs device /home/user04/vol1 quota size is 1G

step 2: modify storage.conf

[storage]
driver = "overlay"
graphroot = "/home/user04/vol1"

[storage.options]
additionalimagestores = ["/opt/containers/storage"]

[storage.options.overlay]
mount_program = "/usr/bin/fuse-overlayfs"

step 3: create a container

sudo -u user04 podman run -it -d --network=none  --name=test12 docker.io/library/ollama-qwen3:1.7b

step 4: add 900MiB files within test12 container

sudo -u user04 podman exec -it test12 /bin/bash
dd if=/dev/zero of=/ccc bs=900MiB count=1

step 5: commit a new image named docker.io/library/test12:v1, however it can not work

sudo -u user04 podman commit 76da6429a230 docker.io/library/test12:v1

Getting image source signatures
Copying blob 470b66ea5123 skipped: already exists  
Copying blob f8774a5d2593 skipped: already exists  
Copying blob 337ddc4ba2c7 skipped: already exists  
Copying blob 6b772d504594 skipped: already exists  
Copying blob 9afecb25982f skipped: already exists  
Copying blob 81a163338a85 done   | 
Error: copying layers and metadata for container "76da6429a230ffacbbb09487cc8cf105f7a9f2ba0b20254ac954a6d92b8f58f7": writing blob: adding layer with blob "sha256:81a163338a85b9adf1fd7c7729ccf8156a597c9e0bf5b3464bb1d92c7bc18a5e"/""/"sha256:81a163338a85b9adf1fd7c7729ccf8156a597c9e0bf5b3464bb1d92c7bc18a5e": unpacking failed (error: exit status 1; output: write /ccc: no space left on device)

the reason for step 5 failed is lvs device size is 1GiB, and i add 900MiB file to container, now test12 container diff is 900MiB, but docker.io/library/test12:v1 image need 900MiB space, so the total size is 900MiB+900MiB is more than lvs device size

i don't want to build user04 image to /home/user04/vol1 where the container stand on ，because it always failed for large modify

am i missing somthing or how can i do to resolve it？

[giuseppe]

2GiB is not really a lot of space, wouldn't be easier to just provision more space to the user?