jrun snapshot¶

Manage ZFS snapshots for jails — create, list, rollback, and delete.

Create a snapshot¶

jrun snapshot create <jail>

Creates a snapshot with an auto-generated UTC timestamp name like 2026-03-19_00-38-14.

jrun snapshot create hypha-redis

Named snapshot¶

jrun snapshot create <jail> <name>

jrun snapshot create hypha-redis before-upgrade

Snapshots are instant and taken while the jail is running — no downtime required. They capture the full jail filesystem at that exact point in time.

List snapshots¶

jrun snapshot list <jail>

jrun snapshot list hypha-redis

name                  used   created
before-upgrade        0B     Wed Mar 19 00:38 2026
2026-03-19_01-15-42   88K    Wed Mar 19 01:15 2026

The used column shows how much data has changed since the snapshot was taken. A snapshot with 0B used means nothing has changed.

Rollback to a snapshot¶

jrun snapshot rollback <jail> <name>

jrun snapshot rollback hypha-redis before-upgrade

Stops the jail, reverts the filesystem to the snapshot, and starts the jail again. Any snapshots newer than the target are destroyed — ZFS does not support rolling back to an older snapshot while keeping newer ones.

Requires confirmation before proceeding.

Delete a snapshot¶

jrun snapshot delete <jail> <name>

jrun snapshot delete hypha-redis before-upgrade

Requires confirmation before proceeding. Fails with a clear message if the snapshot does not exist.