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Maintenance

Delete a snapshot

# Delete a specific snapshot by ID
vykar snapshot delete a1b2c3d4

Delete a repository

Permanently delete an entire repository and all its snapshots.

# Interactive confirmation (prompts you to type "delete")
vykar delete

# Non-interactive (for scripting)
vykar delete --yes-delete-this-repo

Prune old snapshots

Apply the retention policy defined in your configuration to remove expired snapshots. Optionally compact the repository after pruning.

vykar prune --compact

Verify repository integrity

# Structural integrity check
vykar check

# Full data verification (reads and verifies every chunk)
vykar check --verify-data

Repair

vykar check --repair plans and applies fixes for the problems check detects: removing corrupt or dangling snapshots, dropping index entries for missing packs, and (always) rebuilding chunk refcounts from the surviving snapshots.

# Preview the repair plan without changing anything
vykar check --repair --dry-run

# Apply the repair (prompts for confirmation)
vykar check --repair

# Apply non-interactively (for scripting)
vykar check --repair --yes

The refcount rebuild also reclaims the space leak left by an interrupted backup. If a backup crashes after its index was committed but before its snapshot was written, the index keeps orphan chunk entries (and inflated refcounts) that no snapshot references. compact alone will not free these — it treats any in-index chunk as live. vykar check --repair recomputes refcounts from the surviving snapshots and drops the orphan entries; a follow-up vykar compact then reclaims the disk space.

Compact (reclaim space)

After delete or prune, blob data remains in pack files. Run compact to rewrite packs and reclaim disk space.

# Preview what would be repacked
vykar compact --dry-run

# Repack to reclaim space
vykar compact

Sharing one repository between hosts

Several machines can back up to the same repository, but they should run compatible vykar versions. Compatibility is backward-readable, not forward-compatible: a newer binary reads everything older ones wrote, but an older binary cannot read snapshots written by a newer one.

If you see this when listing or backing up:

WARN snapshot 3f9c…: stored envelope has 15 fields, this build reads 14 —
     written by a newer vykar; upgrade vykar on this host. Skipping —
     this repository listing is incomplete
1 snapshot hidden: written by a newer vykar — upgrade vykar on this host to see it

…then another machine using this repository is running a newer vykar than this one. Specifically:

  • Nothing is lost or damaged. The snapshot is intact on the server and fully readable from the up-to-date host. This machine simply cannot decode its metadata, so it leaves it alone.
  • This host’s view of the repository is incomplete. The hidden snapshots are missing from vykar list, and cannot be restored from this machine.
  • The fix is to upgrade vykar on the host printing the warning. Compare vykar --version across your machines and bring the oldest up to date.

Older releases of vykar reported this as a bare deserialization error and silently dropped the snapshot from the listing. If you are running a version older than 0.17.0 alongside newer ones, do not run vykar check --repair on the older host: it misclassifies the unreadable snapshot as corrupt and deletes it. Current versions refuse to repair while any such snapshot is present.