Is it possible to bind mount nested ZFS datasets without storage pool?

Incus
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1

Hi! I’m using incus with zfs and I create multiple ZFS datasets for different data on the host filesystem.

I would like to bind mount these mountpoints of ZFS datasets to incus containers, but I can’t get it to work.

Here are the full steps:

  1. On the host, I’ve created tank dataset and its nested datasets:

    zfs create -o canmount=off rpool/tank 
zfs create -o mountpoint=/mnt/tank/app-data rpool/tank/app-data
zfs create -o canmount=off rpool/tank/dbs
zfs create -o mountpoint=/mnt/tank/dbs/mariadb rpool/tank/dbs/mariadb

  2. copy data to /mnt/tank

  3. bind mount tank to the container on the /mnt/tank path:

    incus config device add docker tank disk source=/mnt/tank path=/mnt/tank shift=true

  4. Then, from inside the container:

    incus exec docker -- su --login ubuntu

  5. Listing /mnt/tank, I can only see directories, no files, and the directories are all owned by root.

    tree /mnt/tank
/mnt/tank
├── app-data
└── dbs
    └── mariadb

4 directories, 0 files

  6. But I create 1.txt in /mnt/tank, it is visible on the host.

I would like to know if it is possible to bind mount nested ZFS datasets to incus containers.

Thanks!

2

I believe we have recursive=true to handle some of that, but I’m not sure how well that plays with shift=true

3

I try it:

incus config device add docker tank disk source=/mnt/tank path=/mnt/tank shift=true recursive=true

Then I’ get it:

[violet@docker ~]$ ls -l /mnt/tank/
total 10
drwxr-xr-x 39 violet violet 39 Dec 31 12:31 app-data
drwxr-xr-x  6 root   root    6 Dec 29 11:22 dbs
drwxr-xr-x  2 root   root    2 Dec 29 11:23 files

It’s very nice. It also works with shift=true.

Thanks!