Check the Current Shadow Copy Storage Location
- Open Command Prompt as Administrator.
- Run:
vssadmin list shadowstorage
Review the output for each volume. You’re looking for:
- For volume: The volume being protected (typically C:).
- Shadow Copy Storage volume: Where the shadow copies are currently stored.
- Used/Allocated/Maximum Space: How much storage is being used.
Example:
For volume: (C:)
Shadow Copy Storage volume: (C:)
If the storage volume is C:, the shadow copies are being stored on the system drive.
Verify the Destination Drive
Before moving the storage:
- Confirm the destination drive (for example S:) has sufficient free space.
- Ensure it is a local NTFS volume.
- Verify the drive will remain connected and available.
Remove the Existing Shadow Storage Association
If shadow storage is currently on C:, remove the association:
vssadmin delete shadowstorage /for=C: /on=C:
If you receive a message stating the association was not found, it may have already been removed.
Create a New Shadow Storage Location
Create the new storage association on the destination drive: Set the size to what is preferable.
vssadmin add shadowstorage /for=C: /on=S: /maxsize=100GB
Replace S: and the size as appropriate for the server.
| Drive Type | Recommended Shadow Copy Size |
| OS Drive (C:) | 10–20 GB (or none if storing elsewhere) |
| Small Data Drive (<250 GB) | 10–15% of the drive |
| Medium Data Drive (250 GB–1 TB) | 10–20% of the drive |
| Large Data Drive (>1 TB) | 100–300 GB, depending on change rate |
| File Server with frequent changes | 15–20% of the volume |
Verify the Change
Run:
vssadmin list shadowstorage
Confirm the output now shows:
For volume: (C:)
Shadow Copy Storage volume: (S:)
This confirms the shadow copy storage has been successfully moved.
Optional Health Checks
Verify the VSS service is running:
sc query vss
Check that all VSS writers are stable:
vssadmin list writers
All writers should report:
- State: Stable
- Last Error: No error
Notes
- This changes where future Volume Shadow Copies are stored. It does not move existing snapshots.
- Existing restore points or snapshots may be removed when the old shadow storage association is deleted.
- If this server is used for backups (such as Cove, Windows Server Backup, etc.), consider running a test backup afterward to verify VSS is functioning normally.
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