ZFS Notes¶

In this document, replace worldsgrave with the name of your zpool.

Recommended settings¶

Compression¶

Use lz4 compression, it's fast and efficient.

zfs set compression=lz4 worldsgrave

Access Time¶

Turn off atime, it's useless.

zfs set atime=off worldsgrave

De-Duplication¶

De-Duplication

NEVER use de-dupe, it's a massive performance hit.

Scheduled Scrubing¶

Create the following files:

/etc/systemd/system/zfs-scrub@.service

[Unit]
Description=zpool scrub on %i

[Service]
Nice=19
IOSchedulingClass=idle
KillSignal=SIGINT
ExecStart=/usr/sbin/zpool scrub %i

[Install]
WantedBy=multi-user.target

/etc/systemd/system/zfs-scrub@.timer

[Unit]
Description=Monthly zpool scrub on %i

[Timer]
OnCalendar=monthly
AccuracySec=1h
Persistent=true

[Install]
WantedBy=multi-user.target

Enable and start the new service:

systemctl daemon-reload
systemctl enable zfs-scrub@worldsgrave.timer

Scheduled Snapshots¶

Install zrepl, see zrepl.yaml for reference.

Useful Commands¶

List datasets¶

zfs list -o type,name,available,used,logicalused,usedbysnapshots,compressratio,mountpoint

List snapshots¶

zfs list -t snapshot

Recordsize¶

 zfs get recordsize -t filesystem

Aliases¶

alias zls="zfs list -o type,name,available,used,logicalused,usedbysnapshots,compressratio,mountpoint"+
alias zsl="zfs list -t snapshot"