Remove the Proxmox Thin Pool and replace with a proper volume

LVM Thin despite all the promise, is a support nightmare and a risk many consider not worth it. Generally in all our deployments, LVM Thin is pulled and replaced with a proper filesystem which is then mounted and shared with proxmox. 

We will assume data is the thin pool, and we're going to replace that with a thick volume and put ext4 on it, mounting it into /mnt/data. You can of course put whatever filesystem you like on it and mount it wherever you wish. 

Remove the thin pool (once you've moved any guests away)

# lvchange -an /dev/pve/data
# lvremove /dev/pve/data

Create a normal volume

# lvcreate -l 100%FREE -n data pve

Make a filesystem

# mkfs.ext4 /dev/pve/data

Mount your filesystem

# mkdir /mnt/data
# mount /dev/pve/data /mnt/data

Make permanent

# blkid /dev/pve/data
/dev/pve/data: UUID="894e7040-75da-4b82-9e15-f6b2dca2ab7a" BLOCK_SIZE="4096" TYPE="ext4"

Add the following line to /etc/fstab

UUID=894e7040-75da-4b82-9e15-f6b2dca2ab7a /mnt/data ext4 defaults 0 2

Making sure to remove any /etc/fstab entry for the old thin pool volumes. 

Reboot