Datasets¶

Dataset Hierarchy¶

tank/
├── media/              # Plex / Jellyfin (large, read-heavy)
├── nextcloud-data/     # User files
├── nextcloud-app/      # App config, apps, themes
├── db/                 # Databases (MariaDB/Postgres)
├── containers/         # Misc container state
├── vm/                 # VM disks
└── backups/

Create Datasets¶

# Media (large files, read-heavy)
sudo zfs create -o recordsize=1M tank/media

# Nextcloud user data
sudo zfs create tank/nextcloud-data

# Nextcloud app config
sudo zfs create tank/nextcloud-app

# Databases (small records)
sudo zfs create -o recordsize=16K tank/db

# Container state
sudo zfs create tank/containers

# VM disks
sudo zfs create -o recordsize=64K tank/vm

# Backups
sudo zfs create tank/backups

Dataset Properties¶

View Properties¶

zfs get all tank/media
zfs get compression,recordsize,quota tank/media

Per-Dataset Tuning¶

Dataset	recordsize	Notes
media	1M	Large sequential files
db	16K	Small random I/O
vm	64K	Balance for VM workloads
(others)	128K	Default, general purpose

Permissions¶

Set ownership for services:

# Nextcloud (www-data is UID 33 in container)
sudo chown -R 33:33 /mnt/tank/nextcloud-data
sudo chown -R 33:33 /mnt/tank/nextcloud-app

# Plex (plex user is UID 997)
sudo chown -R 997:997 /mnt/tank/media

List Datasets¶

# List all datasets
zfs list

# Show with properties
zfs list -o name,used,avail,refer,mountpoint

Nested Datasets¶

Create nested datasets for finer control:

sudo zfs create tank/media/movies
sudo zfs create tank/media/tv
sudo zfs create tank/media/music

Each inherits parent properties but can override them.