ZFS Dataset mount points corrupted

[KevDog]

Here is a list of my specific zfs dataset

#zfs list tank/ZFS-Snapshots/Proxmox 1.31G 22.0T 1.31G /mnt

Why is it mounted at the /mnt mountpoint? How can I change this? I set the dataset up with the GUI. I can't access the dataset on the command line or remount it or frankly even access the dataset...for example. I can't delete it on the FreeNas GUI

# zfs set mountpoint=/mnt/tank/ZFS-Snapshots/Proxmox tank/ZFS-Snapshots/Proxmox
cannot unmount '/mnt': Device busy

 

[Chris Moore]

Why is it mounted at the /mnt mountpoint?

That is where FreeNAS mounts all storage pools.

How can I change this?

You can't, as long as you are using FreeNAS. Why would you even think about it?
You are trying to do something so totally wrong that I can't even understand what you are trying to do.

Please try to explain yourself so we can tell you what you are supposed to be doing because this is wrong.

 

[KevDog]

Yes I know it's very very wrong

I have one zpool --- tank.
Within tank I have multiple datasets. I created the datasets with the GUI
One of the datasets I created with the GUI was tank/ZFS-Snapshots/Proxmox. You can see this listed in the picture above. My belief is that this should be mounted at /mnt/tank/ZFS-Snapshots/Proxmox.

The problem is that Freenas or zfs or some process screwed up. I wasn't creating anything on the command line. Unfortunately the tank/ZFS-Snapshots/Proxmox datapoint is now mounted as /mnt.

Code:

root@freenas:/boot # zfs mount
freenas-boot/ROOT/11.2-U2       /
tank/ZFS-Snapshots/Proxmox      /mnt
tank                            /mnt/tank
tank/TimeMachine                /mnt/tank/TimeMachine
tank/ZFS-Snapshots              /mnt/tank/ZFS-Snapshots

This configuration makes no sense. I want to either delete or remove or change where tank/ZFS-Snapshots/Proxmox is mounted. In fact I can just delete the dataset -- if I could. I can't do anything now with the dataset because of the mountpoint. I can't delete it within the GUI or change the mountpoint, or even do these things at the command line. I have no idea how /mnt was assigned as the mountpoint -- clearly there is a problem because the GUI above doesn't reflect what the command line is showing in terms of mountpoint.

Here is my zpool list

Code:

# zpool list
NAME           SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
freenas-boot  59.5G  10.2G  49.3G        -         -      -    17%  1.00x  ONLINE  -
tank          43.5T  5.36T  38.1T        -         -     6%    12%  1.00x  ONLINE  /mnt

 

[Chris Moore]

The problem is that Freenas or zfs or some process screwed up. I wasn't creating anything on the command line. Unfortunately the tank/ZFS-Snapshots/Proxmox datapoint is now mounted as /mnt.

Did you do a ZFS send to push a snapshot from somewhere else into this Proxmox dataset?

Before you try this, make sure nothing is actively trying to access your storage.

Have you tried exporting the pool?
https://www.ixsystems.com/documentation/freenas/11.2/storage.html#export-disconnect-a-pool
It is possible, that exporting the pool (do not clear it) will allow you to import it again:
https://www.ixsystems.com/documentation/freenas/11.2/storage.html#importing-a-pool
This could clear up the incorrect mount location. If it doesn't, it may free the lock so the zfs set mountpoint command will work from the command line.

 

[Chris Moore]

PS. also, do not delete the share configuration. If you export the pool without deleting share config, you just stop and start the SMB service to get the share back working.

 

[KevDog]

PS. also, do not delete the share configuration. If you export the pool without deleting share config, you just stop and start the SMB service to get the share back working.

I see what you are talking about -- this is my main pool. There is no other pool. Is this what you want me to do? And how do I reconnect the pool?

 

[Chris Moore]

I see what you are talking about -- this is my main pool. There is no other pool. Is this what you want me to do? And how do I reconnect the pool?

Yes. Exporting the pool un-mounts the dataset. The next step is the second link where you Import the pool:
https://www.ixsystems.com/documentation/freenas/11.2/storage.html#importing-a-pool

 

[KevDog]

Ok -- I exported and reimported the pool, however its at the same point. Still mounted at /mnt. I tried the zfs set mountpoint command however keep getting the error:
cannot unmount '/mnt': Device busy

 

[KevDog]

Alright -- mucho thanks for mounting me in the right direction. With some trying alot of options this is what I did:

Code:

# zfs set canmount=off tank/ZFS-Snapshots/Proxmox  <---Which disables auto-mounting

I then exported and then re-imported the pool as you described

Code:

# zfs set mountpoint=/tank/ZFS-Snapshots/Proxmox tank/ZFS-Snapshots/Proxmox
# zfs set canmount=on tank/ZFS-Snapshots/Proxmox
# zfs mount tank/ZFS-Snapshots/Proxmox

And surprisingly all the data was still there!!!

Here is the original zfs replicate command I sent from the Proxmox box:

Code:

# zfs send -Rv rpool/ROOT/pve-1@initproxmox | ssh FreeNAS zfs recv -F tank/ZFS-Snapshots/Proxmox

What did I do wrong?