Work with snapshots - DeltaSnap Docs

Create a snapshot

Select a writable Data volume, open Snapshots, and choose Create. An optional label makes the checkpoint easier to recognize; the kernel name and numeric XID remain its authoritative identity.

DeltaSnap Snapshots tab with the create, delete, compare, analyze, and reveal toolbar above a table of snapshots showing created time, label, kind, expiry, private size, and indexed state. — The **Snapshots** tab lists every native APFS snapshot on the volume with its kind, expiry, storage measurements, and index state.

Choose a disposition:

Safety Snapshot (Auto-expiry) is the default and expires after the global safety retention period (24 hours by default).
Protected Snapshot is held against every automatic pruner and requires extra confirmation to delete.

The CLI creates a non-expiring manual snapshot by default:

dsnap snapshot data@before-upgrade

Use --safety for an auto-expiring script or agent checkpoint:

POINT=$(dsnap snapshot --safety data@ai-pre-upgrade)
dsnap tag "$POINT" '{"agent":"codex","phase":"pre"}'

Each snapshot can carry one searchable free-form tag. Right-click a row to add, edit, or clear it; use dsnap tag and dsnap tags for automation. JSON tags are useful for session metadata.

Snapshot kinds

Kind	Lifecycle
Safety	Fixed TTL from Settings → General; used for casual checkpoints, restores, merges, and monitoring alarms
Automatic	Rotated by active cadence counts, or natural lifespan when no active count covers it
Manual	No time expiry; eligible only for low-space pruning unless protected
External	Created by Time Machine, CCC, or another tool; protected from DeltaSnap pruning by default
System	`com.apple.os…` rollback snapshot; hidden or excluded from DeltaSnap deletion

Protect and unprotect

Protection overrides every automatic deletion path. Right-click one or more snapshots and choose Protect Snapshot(s). Release protection only when the snapshot can return to its normal lifecycle.

dsnap hold data@HEAD
dsnap unhold data@HEAD
dsnap holds data

For movable external volumes, DeltaSnap stores protection on the volume when macOS permits it so the hold travels with the disk. Internal startup-volume protection is stored locally because SIP restricts the volume root.

Mount and reveal

Mounting exposes a read-only historical tree under /Volumes. DeltaSnap reuses managed mounts across Version Control, Quick Look, Finder, and comparisons, and does not unmount one while another feature still has a lease.

Delete snapshots

Deletion is permanent. Select snapshots, choose Delete, and review protected, mounted, or foreign targets carefully. Automatic pruning skips mounted/in-use snapshots and retries later.

dsnap destroy data@HEAD~2
dsnap destroy --force data@HEAD~2

--force can unmount a target and bypass its individual protection. It does not make hidden macOS rollback snapshots eligible. See Schedules and retention before enabling automatic deletion.