Frequently Asked Question
Why can I not delete a file or shared folder protected by Synology WriteOnce?
QUICK ANSWER
WriteOnce protects retained data deliberately. Check the file's lock and retention state and the folder's Enterprise or Compliance mode before treating the result as an ordinary permission fault.
Applies to: DSM 7-series systems and Btrfs volumes that support WriteOnce. Immutable snapshots are a different protection layer.
Identify what is protected
In File Station, confirm that the affected item is inside a WriteOnce shared folder. Record whether the operation concerns one file, the complete shared folder or a snapshot. A normal folder-access problem needs a different diagnosis.
Read the retention state
Check the selected file's WriteOnce information and the folder's configured retention. A locked file cannot simply be overwritten or removed by granting a stronger account more access. Keep the original data and record the displayed state.
Check the folder mode
Enterprise and Compliance modes have different administrative deletion restrictions. Compliance mode also protects the containing storage structure. Do not assume a permission change or an administrator sign-in makes either mode behave like a normal share.
Allow for the protection clock
Retention uses a tamper-resistant clock. The effective protection period can extend beyond a wall-clock estimate, including periods when the system was not running. Check the recorded expiry instead of repeatedly trying deletion.
Plan the legitimate next step
If the protection period is still active, preserve the archive and agree an alternative writable location for new work. If a supported deletion remains unavailable after expiry, collect the exact mode, status and software version for review before changing the storage structure.
Confirm the result
Confirm the displayed lock/retention state explains the rejected operation, and that a separate ordinary writable test folder works. This distinguishes retention from a general access problem without altering protected records.
Before going further: Do not change the system clock, delete the volume or storage pool, or try a reset to bypass retention. Obtain approval from the record owner before any operation affecting retained information.
If you need help
Include these details in your ticket: NAS model, DSM version, WriteOnce mode, affected operation, displayed expiry and a redacted screenshot. Keep document contents and business records private.
Related guidance: Why is Delete unavailable for an immutable Synology snapshot? · File Sharing: How to set up user's privilege for shared folders on Synology NAS?
Updated 261110