Cannot create mount on Mac sequoia

[JonnyPanic]

Hi, please help, I can't mount a ZFS drive, I run the mount command...

sudo zpool import -f Pool1 -d /dev -o readonly=off altroot=/mnt/Pool1

and get this response...

cannot mount '/mnt/Pool1/mnt/Pool1': failed to create mountpoint: Read-only file system
Import was successful, but unable to mount some datasets

I'm trying to mount one half of a mirror from a trueNAS server, no encryption on my MAC (Seqoia, openZFS 2.3.0).

The pool is imported....

zpool status -v Pool1
pool: Pool1
state: DEGRADED
status: One or more devices could not be opened. Sufficient replicas exist for
the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-2Q
scan: scrub repaired 128K in 05:50:08 with 0 errors on Tue Aug 5 05:50:11 2025
config:

NAME STATE READ WRITE CKSUM
Pool1 DEGRADED 0 0 0
mirror-0 DEGRADED 0 0 0
8736212223073055591 UNAVAIL 0 0 0 was /dev/disk/by-partuuid/b2dc0c75-b5ef-4a76-9e56-583120f570fb
disk10s1 ONLINE 0 0 0

errors: No known data errors


And readonly is off

zfs get readonly Pool1
NAME PROPERTY VALUE SOURCE
Pool1 readonly off local


Why can't I mount the dataset?

[JonnyPanic]

ah solved it... "Volumes" on a mac not "mnt"

Import should have been this...

sudo zpool import -f Pool1 -d /dev -o readonly=off -R /Volumes/Pool1

Now getting a permsion error...

[glessard]

You can create a mount point directly in / by configuring apfs.util; see `man synthetic.conf`.
I have my main zfs pool mounted at the top level thanks to this feature.