zpool list
zpool list <poolname>
zpool status
zpool status -x
zpool status -v <poolname>
zpool iostat
zpool iostat -v
zpool history

Rule of thumb:
2 GB + 1GB Cache per 1 TB Storage

Set Cache Min/Max

cat << 'EOF' > /etc/modprobe.d/zfs.conf
options zfs zfs_arc_min=3221225472
options zfs zfs_arc_max=4294967296
EOF

update-initramfs -u && reboot

4x NVMe as VM datastore (Hypervisor installed on nvme0n1 and nvme1n1)

zpool create -o ashift=12 -O compression=lz4 -O atime=off -O xattr=sa -O local-datastore-nvme01 mirror /dev/nvme2n1 /dev/nvme3n1 mirror /dev/nvme4n1 /dev/nvme5n1

Parameters

ashift=12              # Aligns to 4K sectors (SSD optimal)
autotrim=on	       # Enables TRIM for SSDs (optional - alternatively create cronjob running during off-peak hours)
compression=lz4	       # Transparent compression, fast
atime=off	       # Disables access time writes
xattr=sa	       # Stores xattrs in inode — good for VMs