Synology Hyper Backup / Troubleshooting
Synology Hyper Backup Insufficient Destination Quota
Inspect retained versions and destination usage before choosing a capacity or retention procedure, without deleting recovery points as a diagnostic test.
Start with the destination-storage message, not the duration of the backup. Retained history may consume additional space, but that possibility is not proof that particular versions should be removed.[1]
Applicability
- Products
- Synology DSM · Synology Hyper Backup
- Scope
- For DSM 7 Hyper Backup reporting insufficient storage at its backup destination. Retention analysis applies to multi-version tasks. Destination-capacity handoffs differ for Synology NAS, USB, current C2 OneStorage plans, legacy C2 Storage subscriptions during their transition, and other providers; no universal free-space threshold or account-quota cause is assumed.[1][3]
- Last verified
Symptoms
- Hyper Backup reports insufficient storage or quota at the destination. This page does not diagnose an offline target or a connection failure from that wording alone.[1]
Quick diagnosis
Start with the recorded state and preserve the evidence before choosing a next action.
Record the message and destination
Identify the affected task and actual destination before choosing between retention and capacity procedures.[1]
Inspect destination usage separately from source size
In Backup Statistics, compare Destination Usage with Source Disk Usage. They describe different sides of the task; the current source size alone does not describe retained backup history.[2][1]
Interactive troubleshooter
Your answers stay in this browser tab. The tool does not connect to your systems or send diagnostic results.
Guided check / step 1
Safe diagnostic guidanceIs the message about insufficient destination storage?
Read the actual message before treating this as a capacity issue.[1]
Read the complete diagnostic tree without using the controls
- Is the message about insufficient destination storage?
Read the actual message before treating this as a capacity issue.[1]
- Yes → Which retention situation applies?
- No, or uncertain → Clarify the reported error
- Which retention situation applies?
Inspect the task and version inventory without modifying rotation.[3][2]
- Multi-version task; some history could be reduced if explicitly approved → Has reducing backup history been explicitly approved?
- All recovery points must remain, or this is not a multi-version task → Which destination needs a capacity plan?
- I do not know which recovery points must remain → Decide what backup history must be preserved
- Has reducing backup history been explicitly approved?
This is a planning decision, not a request to delete versions now.[3]
- Yes → Use a separately reviewed retention procedure
- No → Which destination needs a capacity plan?
- Which destination needs a capacity plan?
The vendor's capacity branches are destination-specific.[1]
- Synology NAS → Plan NAS capacity work separately
- External USB → Review the USB migration requirements
- Synology C2 → Confirm the applicable C2 plan path
- Another service or provider → Confirm the provider's capacity path
- Unknown → Decide what backup history must be preserved
- Clarify the reported error
Do not choose a storage-change procedure without the matching destination-storage message.[1]
- Decide what backup history must be preserved
Preserve the task evidence and current versions until the capacity-versus-retention decision is established. Do not delete versions merely to test whether the task resumes.[1][3]
- Use a separately reviewed retention procedure
Check task-state restrictions and immediate-rotation consequences before the approved procedure. No deletion is performed by this tree.[3][2]
- Plan NAS capacity work separately
Record destination usage, the current version inventory and the requirement to preserve history, then use the NAS capacity branch. This diagnosis does not prescribe a storage-pool change.[1][2]
- Review the USB migration requirements
Record the current repository, destination usage and version requirements, then use the official USB branch as a separate migration procedure. Do not treat repository movement, relink or Discard as a generic shortcut.[1][2]
- Confirm the applicable C2 plan path
Identify whether the account uses current OneStorage or a legacy C2 Storage subscription, then follow the plan-specific capacity guidance in the current Synology quota documentation. Do not assume legacy plan availability or initiate a purchase from this diagnosis.[1]
- Confirm the provider's capacity path
Record the provider, the reported quota/capacity message and the retention requirement, then use that provider's current capacity guidance. No universal third-party quota setting is assumed here.[1]
Detailed diagnosis
1. Inventory recovery points without removing them
Use Version List to inspect dates, status and locked versions. Establish which recovery points must be retained before considering a retention change.[2][3]
2. Read the existing rotation policy
For a multi-version task, inspect the configured rotation mode and maximum version count without saving changes. Locked versions are excluded from that count and are not removed by rotation.[3]
3. Check whether task state limits version management
Record whether the task is suspended or Restore Only. These states have version-management restrictions; do not bypass them by deleting destination files.[2]
Supported scenarios
Match each explanation to the observation before treating it as the diagnosis.
Retained versions contribute to destination usage
Historical backup versions can add storage consumption beyond the current source data.[1]
How to check: Compare the destination usage and version inventory before choosing a response.[2]
The version count does not include locked versions
Rotation preserves locked versions and excludes them from the maximum-version calculation.[3]
How to check: Inspect locks and policy together; do not unlock recovery points just to make a count match.[3]
Next actions and procedure boundaries
Select a destination-specific capacity procedure
Consult the quota source for the matching NAS, USB, C2 or other-provider branch. For C2, confirm whether the account uses current OneStorage or a legacy C2 Storage subscription before choosing a plan-specific procedure. Storage expansion, USB migration/relink and subscription changes are separate operations, not read-only tests performed by this page.[1]
Review retention requirements before any deletion
If history may be reduced, first decide which recovery points must remain. Read the official retention procedure before changing anything: rotation can run immediately after a setting change. This page provides no deletion sequence or promised undo.[3][1]
Keep unresolved capacity findings explicit
If the destination or required retention is unknown, preserve the evidence and decide what must be kept before changing storage or history. For non-Synology devices or services, the quota source directs users to their provider.[1]
Warnings and boundaries
Sources
Links were reviewed on 2026-09-05. Reachability and automated validation do not replace editorial verification of each claim.
- What can I do if I am informed of insufficient quota of backup destination when using Hyper Backup?
Synology · Tier A · accessed 2026-09-05 - Backup Tasks
Synology · Tier A · accessed 2026-09-03 - Settings
Synology · Tier A · accessed 2026-09-03