How to Backup PST Files While Outlook is Open?

Backing up PST (Personal Storage Table) files in Outlook is a critical task for anyone who relies on the application for managing emails, contacts, calendars, and other important data. However, one of the challenges users often face is the need to back up these files while Outlook is open and in use.

Since it is critical to perform the backup process while MS Outlook is open and using the PST file, we need to learn how to backup PST files without harming the process. This guide will walk you through various methods and best practices to ensure your PST files are safely backed up without interrupting your workflow.

Understanding PST Files

PST files are used by Microsoft Outlook to store local copies of messages, calendar events; and other items. These files are crucial for data integrity and recovery in case of corruption or accidental deletion. Ensuring regular backups of PST files can prevent data loss and make recovery smoother in case of an issue.

Why Backup PST Files While Outlook is Open?

Backing up PST files while Outlook is open can be necessary for several reasons:

  1. Continuous Operations: Many users need Outlook to remain open for real-time email communication and scheduling.
  2. Automated Backup Solutions: Some backup software solutions are designed to operate continuously and might need access to PST files even when Outlook is in use.
  3. Minimized Downtime: For businesses, especially those with large email volumes, closing Outlook for backups can lead to significant downtime.

Why it is a Challenge to Copy a PST file when Outlook is Open?

Backing up PST (Personal Storage Table) files while Outlook is open presents several unique challenges due to the nature of how these files are managed and accessed by the Outlook application. Here are the primary issues involved in this process:

1. File Locking and In-Use Files

When Outlook is open, PST files are actively being used and locked by the application. This can create several problems:

  • Access Denied Errors: Backup software may encounter errors because it cannot access the file that is currently locked by Outlook.
  • Incomplete Backups: Even if the backup software manages to copy the file, the data within the PST may not be in a consistent state, leading to incomplete or corrupted backups.

2. Data Consistency Issues

Active use of Outlook means the PST file is constantly changing:

  • Dynamic Changes: Emails, calendar events, and other data are frequently added, modified, or deleted. Backing up a file that is constantly changing can result in an inconsistent snapshot.
  • Transaction Logs: Outlook maintains transaction logs to keep track of changes. If a backup is taken while transactions are pending, the backup might not reflect the latest state.

3. Performance Impact

Backing up large PST files while they are in use can impact system performance:

  • Resource Consumption: Copying large files requires significant CPU, memory, and disk I/O resources, which can slow down the system and affect other operations.
  • User Experience: If Outlook performance degrades due to backup activities, it can disrupt user productivity.

4. Risk of Data Corruption

Interacting with a PST file during backup increases the risk of PST file corruption:

  • File Integrity: If Outlook writes to the PST file while it is being copied, the resulting backup may be corrupted or unusable.
  • Backup Failures: Incomplete or interrupted backup processes can lead to partially copied files, which may not restore correctly.

5. Backup Software Limitations

Not all backup software is equipped to handle PST files that are in use:

  • Lack of VSS Support: Some backup solutions do not support Volume Shadow Copy Service (VSS), which is necessary for copying open files.
  • Compatibility Issues: Backup software must be compatible with the version of Outlook and the format of the PST file.

6. Incremental Backup Challenges

PST files do not lend themselves well to incremental backups:

  • Whole File Backup: Many backup solutions treat PST files as a single entity, requiring the entire file to be backed up even for minor changes.
  • Inefficiency: This approach can lead to large backup files and inefficient use of storage space.

7. Scheduling Conflicts

Scheduling regular backups can be problematic if Outlook is in constant use:

  • User Availability: Finding a time when Outlook is not in use for backups can be difficult, especially in environments where email access is required around the clock.
  • Automated Backups: Setting up automated backups while ensuring they do not interfere with Outlook’s operation requires careful planning.

How to Backup PST Files While Outlook is Open?

1. Using Windows Backup Software with VSS (Volume Shadow Copy Service)

Volume Shadow Copy Service (VSS) is a Windows feature that allows creating the backups of files even when they are in use. Here’s how to use it for backing up PST files:

  1. Choose Backup Software: Select a backup solution that supports VSS. Examples include Acronis True Image, Macrium Reflect, and ShadowProtect.
  2. Configure Backup Job: Set up a backup job targeting the directory where your PST files are stored. Ensure the software is configured to use VSS for file access.
  3. Schedule Regular Backups: Schedule backups at regular intervals, ensuring minimal performance impact during peak hours.

2. Using Outlook AutoArchive and Export Features

Outlook’s built-in AutoArchive and Export features can be used to create backups without fully closing Outlook:

  1. AutoArchive:
  2. Go to File > Options > Advanced > AutoArchive Settings.
  3. Configure AutoArchive to run periodically, specifying the location where archived items should be saved.
  4. Export:
  5. Go to File > Open & Export > Import/Export.
  6. Choose Export to a file and select Outlook Data File (.pst).
  7. Select the folders to export and specify the destination for the exported PST file.
  8. This method can be used to create manual backups without disrupting Outlook usage.

3. Using Third-Party PST Backup Tools

Several third-party tools are designed specifically for backing up PST files without needing to close Outlook. These tools often provide more flexibility and advanced options compared to built-in methods.

4. Manual Copy with Shadow Copies

For users comfortable with more advanced techniques, manually creating shadow copies and copying PST files can be an option:

  1. Create a Shadow Copy:
  2. Open Command Prompt as an administrator.
  3. Use the command: vssadmin create shadow /for=C:
  4. Locate the Shadow Copy:
  5. Use the command: vssadmin list shadows to find the shadow copy.
  6. Copy PST Files:
  7. Navigate to the shadow copy directory and manually copy the PST files to your backup location.

Best Practices for Backing Up PST Files

  1. Regular Backups: Schedule backups at regular intervals, ensuring you always have up-to-date copies of your data.
  2. Test Restorations: Periodically test your backups by restoring files to ensure they are usable and not corrupted.
  3. Secure Backup Locations: Store backups in secure locations preferably with offsite or cloud-based solutions for disaster recovery.
  4. Monitor File Sizes: Keep an eye on the size of your PST files and reduce the PST file size when increases, because the large files can be prone to corruption and may require splitting or archiving.


Backing up PST files while Outlook is open is a manageable task with the right tools and methods. Whether you use VSS-enabled backup software, Outlook’s built-in features, third-party tools, or manual techniques, ensuring regular and reliable backups is crucial for data integrity and peace of mind. By following the methods and best practices outlined in this guide, you can maintain seamless email operations while safeguarding your valuable Outlook data.

Related Posts