documentation/docs/alpine-server-setup/post-install/update-protocol.md

Update protocol

ZFS opens up new methods to safely update the system. These methods are described in this section in combination with general practises to maintain ZFS filesystems.

Pre-update

To be able to rollback the system after a system update one may create a snapshot of the root filesystem.

# zfs snapshot tank/root/alpine@previous

Tip: zfs destroy can be used to remove snapshots and zfs list -t snapshot can be used to list them.

Update

Perform a system update.

# apk upgrade
# reboot

If the system does not behave accordingly after reboot, one may rollback to the previous snapshot and further investigate from there.

# zfs rollback -r tank/root/alpine@previous

Post-update

To maintain the performance of the SSDs in the system, perform a trim on the zfs-pool.

# zpool trim --secure --wait tank

Some devices may not support the option --secure, remove it then, if necessary.

Thereafter, perform a scrub on the zfs-pool which checks and repairs the data in the pool.

# zpool scrub tank

This may take a while, the progress can be checked with:

# zpool status tank

A ZFS scrub only repairs if mirror or a zraid mode is used in the pool.