Add a dataset named Stuff under the Data pool.
zfs create Data/Stuff
Add a dataset for ValKey (Redis) named valkey under the Data pool and mount it at /var/db/valkey
zfs create -o mountpoint=/var/db/valkey Data/valkey
Add a dataset named OpenSearch under the Storage pool, but do not allow it to be mounted and don't set a mountpoint. Set default compression property as lz4 to be inhearited by children
zfs create -o mountpoint=none -o canmount=off -o compression=lz4 Storage/OpenSearch
Add a dataset named Data under the Storage/OpenSearch dataset and mount it at /var/db/opensearch. (Note: if the parent has compression=lz4, this dataset will inherit that property)
zfs create -o mountpoint=/var/db/opensearch Storage/OpenSearch/Data
Add a dataset for MariaDB (MySQL) with a block size of 16k and 2 copies of all data, while setting compression to lz4
zfs create -o mountpoint=/var/db/mysql -o compression=lz4 -o recordsize=16k -o copies=2 Data/mariadb
Here's a tip that will prevent a disater should your dataset not mount (for whatever reason). This command uses extended atrributes to lock the directory so nothing (not even root) can write to it.
# Make sure you run this BEFORE creating or mounting your dataset
install -d /path/to/location
chflags schange /path/to/location
To undo the above, just run
# Make sure your dataset is not mounted BEFORE running this
chflags noschange /path/to/location