Datasets
zfs craete <dataset>
Snapshots
# Create snapshot
zfs snap <volume>@<snapshot_name>
# Delete snapshot (dry-run)
zfs destroy -vn <volume>@<snapshot_name>
# List snapshots
zfs list -t snapshot
# Restore snapshot
zfs rollback <volume>@<snapshot_name>Dataset Properties
Record Size
Note
The default 128KiB is good enough for most cases. See also ZFS Compression Test.
General rules of thumb:
- 1MiB for general-purpose file sharing/storage
- 1MiB for BitTorrent download folders—this minimizes the impact of fragmentation!
- 64KiB for KVM virtual machines using Qcow2 file-based storage
- 16KiB for MySQL InnoDB
- 8KiB for PostgreSQL
See https://klarasystems.com/articles/tuning-recordsize-in-openzfs/.
Compression
# List current compression config
zfs get compression
# Set zstd compression
zfs set compression=zstd pool[/component]
# Inherit from parent
zfs inherit compression pool[/component]Applying to Existing Data
compression and deduplication can be applied to existing data with filerewrite, but recordsize change can not be applied in-place.
Rescue Mount
Linux
mount -o zfsutil -t zfs <dataset> <mountpoint>