Related Ticket: #6220

Overview

Cove backups may fail or complete with errors indicating that files (often SQL-related or tax software database/temp files) are “in use by another process.”

This is most commonly seen with accounting/tax applications (e.g., Accounting CS), where background database activity interferes with snapshot-based backups.

Symptoms

You may see the following in Cove:

  • Backup completes with errors
  • Repeated failures on specific files
  • Error message similar to:
    • “The process cannot access the file because it is being used by another process”

Common file types involved:

  • SQL database files (.mdf, .ldf)
  • Temp database files
  • Application-specific database components (Accounting CS, etc.)

Resolution

Step 1 – Restart Backup-Related Services

Reset the Windows Backup Engine and VSS services:

net stop wbengine
net stop vss
net stop swprv

net start swprv
net start vss
net start wbengine

Notes:

  • wbengine = Windows Backup Engine (key factor in this case)
  • vss = Volume Shadow Copy Service
  • swprv = Microsoft Software Shadow Copy Provider

Step 2 – Manually Run Backup

  • Trigger a manual backup
  • Confirm successful completion

Step 3 – Monitor Scheduled Backup

  • Leave auto-backup enabled
  • Verify next scheduled run completes successfully

When to Use This Fix

  • Backup errors reference “file in use”
  • Files are tied to SQL or database-driven applications
  • Issue repeats across multiple runs
  • Manual retries alone do not resolve it
  • Issue clears after service restart

Root Cause (Observed Behavior)

Based on troubleshooting from this case:

  • The issue is triggered when an application keeps a database file “active” during backup
  • Even though VSS is designed to handle open files, something in the backup chain can become unstable
  • When a disconnect or interruption occurs, related services (especially backup engine components) may get into a bad state
  • Once this happens, backups continue to fail until services are reset

There is no confirmed root cause from N-able, even after reviewing debug logs
→ Behavior is intermittent and not fully explained by vendor support

Key Takeaways

  • Often tied to database activity, not just simple file locks
  • The backup engine (not just VSS) can get stuck in a bad state
  • Restarting wbengine alongside VSS is the critical step
  • Issue is intermittent and not fully understood by N-able

Optional Preventative Considerations

  • Schedule backups outside business hours when possible
  • Ensure database-heavy applications are closed overnight
  • Watch for recurring patterns tied to specific software