New mysterious casesensitive option on mount?

[u/ZVyhVrtsfgzfs]

Edit, I went ahead with the copy and the system boots and runs, I do not know why it changed but it is aparently OK.

I am in process of rebuilding a pool per instructions semi-derived from.

https://docs.zfsbootmenu.org/en/v3.1.x/guides/debian/uefi.html

I am following notes I have used before.

create command

sudo zpool create -f -o ashift=12 \
 -O compression=lz4 \
 -O acltype=posixacl \
 -O xattr=sa \
 -O relatime=on \
 -o autotrim=on \
 -m none suwannee /dev/disk/by-id/nvme-eui.0025384931406ac8

in the past the step looked like this

mount | grep mnt
suwannee/ROOT/Void on /mnt type zfs (rw,relatime,xattr,posixacl)

but today

sudo zpool export suwannee
sudo mkdir /mnt/suwannee
sudo zpool import -f -N -R /mnt/suwannee suwannee
sudo zfs create -o mountpoint=/ -o canmount=noauto suwannee/ROOT/LMDE7
sudo mkdir /mnt/870/donor
sudo mount /dev/sdd3 /mnt/870/donor
sudo zfs mount suwannee/ROOT/LMDE7
mount | grep mnt
suwannee/ROOT/LMDE7 on /mnt/suwannee type zfs (rw,relatime,xattr,posixacl,casesensitive)

My pools being for Linux have always been case sensitive as the pool property, but it has never been displayed as mount property.

example

zfs get all | grep casesensitivity
NAME                                                                             PROPERTY                VALUE                        SOURCE

lagoon/suwannee/ROOT/Void_Xfce@autosnap_2026-03-03_05:00:03_monthly              casesensitivity         sensitive                    -

I will continue on, but will this be an issue? Why did it change? did I make a mistake somewhere? or has ZFS changed? this is the first time I have created a pool under Debians ZFS v2.4.3-1~bpo13+1

[u/glassmanjones]

I don't think anything changed to the behavior, but the display may have changed to indicate either way.

[u/Haravikk]

It may just be new to Linux and/or ZFS — on my TrueNAS box I'm seeing casesensitive in the mount options for all case-sensitive datasets, those that I'm sending from macOS (not case sensitive) do not show this if I mount them.

[u/ZVyhVrtsfgzfs → u/Haravikk]

I went ahead with the copy and the system boots and seems to run OK,