Frequently Asked Question
Why is my Synology volume still full after I delete files?
ACE SUPPORT · SYNOLOGY
Deleting a visible file does not always release its blocks immediately. Recycle bins, snapshots, Synology Drive versions and background Btrfs space reclamation can retain space. Find the owner of the usage before deleting recovery history.
Applies to
DSM 7.x shared-folder storage. Btrfs space reclamation applies only to Btrfs volumes. iSCSI LUN reclamation needs a separate workflow.
Before you begin
Deleting versions or snapshots permanently removes recovery options. Immutable retention may prevent removal until expiry. A restart requires a planned service interruption and is not a substitute for diagnosis.
Work through these checks
- Record the affected volume, current free capacity and whether Storage Manager reports a warning. If essential services cannot write, reduce optional incoming jobs while you investigate rather than continuing bulk uploads.
- In Storage Manager, inspect the volume Usage Details. Compare Shared Folder, Synology Drive and Snapshot usage. A small set of visible folders does not prove that package data or historical copies are small.
- Review the affected shared-folder recycle bins, including user home bins, and check what must be recoverable. Empty only items that the data owner has approved for permanent deletion and that are covered by a verified backup.
- If Snapshot Replication or Drive is retaining the data, review its retention settings with the administrator. Keep required recovery points. Do not manually remove hidden package directories or delete all snapshots to make the number fall.
- For Btrfs, inspect Storage Manager > Storage > Global Settings and the Space Reclamation Schedule. Allow an appropriate off-peak window, then give background deletion and reclamation time to finish.
Confirm the result
Compare Usage Details and free capacity again after the allowed reclamation period. Record the change and confirm applications can save normally. There is no fixed completion time for every library or volume.
When to contact us
Escalate if usage remains unexplained, a package reports database errors, or the pool is degraded. Provide before/after capacity, retention settings and the deletion time to our Support Specialist.
Updated 261001