Shadow Copy en Windows

Definition
The function of Shadow Copy, also known as Shadow copy O Volume Shadow Copy Service (VSS), It is a Microsoft technology that allows you to create instant backup copies of files and disc volumes in Windows operating systems. Introduced in Windows XP and improved in later versions like Windows Vista, Windows 7, Windows 8, Windows 10 y Windows Server, This feature allows users and administrators to make data backups without interrupting access to this data. VSS achieves this by taking data of the data in a coherent state, which allows the recovery of files and folders even when these are in use.

Shadow Copy Service Volume Architecture

VSS components

Volume Shadow Copy Service is based on several components that work together to provide shade copy features. These components include:

1. VSS services: The main service that manages the snapshots and coordinates the interactions between the applications that request shadow copies and the volumes containing the data.

2. VSS suppliers: These are the entities that create shadow copies. They can be software suppliers (including those integrated in Windows) o Hardware suppliers that use specific technology for SnapShots at disc level.

3. VSS writers: They are applications that guarantee that the data is in a consistent state during the creation of the shadow copy. For example, database applications such as Microsoft SQL ServerSQL Server is a relational database management system developed by Microsoft. Its design allows it to handle large volumes of data efficiently, facilitating both the administration and retrieval of information. Offers advanced tools for security, performance and scalability, making it a popular choice for businesses of various sizes. What's more, It has support for multiple programming languages ​​and is.... They have VSS writers who ensure that the database is correctly saved.

VSS workflow

VSS's workflow can be summarized in the following steps:

1. Preparation: When an application requests a copy of shadow, VSS begins the preparation of the corresponding volume. This implies that VSS writers prepare for snapshot, Taking a coherent state of the data.

2. Freezing: VSS can "freeze" The data, Which means that writing activity temporarily interrupts to ensure that the copy is consistent. During this brief period, snapshots are taken.

3. Creation of snapshot: Once the data is in a frozen state, VSS creates the shadow copy. This operation can be very fast, since only the state of the volume is recorded and, later, The differences that occur.

4. Defrosting: Once the shadow copy has been created, writing activity resumes in volume, allowing applications and users to continue working without interruptions.

5. Cleaning: Finally, VSS eliminates obsolete shadow copies and releases disk space according to configured policies.

Types of shadow copies

Complete shadow copies

Complete shadow copies are snapshots that capture the entire content of a volume at a given time. This type of copy is commonly used to make complete backup copies of the system or critical data. However, Its use may require a significant amount of disk space.

Incremental shadow copies

Incremental shadow copies, on the other hand, They only capture the changes made from the last copy of shadow. This makes them more efficient in terms of disk space and creation time, since only differences are stored. This type of copy is useful for programmed backups, where time and space are critical considerations.

Copies of differential shadow

Differential shadow copies are a combination of the previous two; They capture all the changes from the last copy of complete shadow. This means that, Instead of just the changes from the last copy of shadow, All changes made from the last complete copy are captured. Although they occupy more space than the incremental, are less expensive to restore.

Shadow Copy implementation in Windows

Shadow Copy habilitation

To enable the shade copy function in Windows, Administrators can follow these steps:

1. Access to shade copies configuration:

   • Access "this PC" o "Mi PC".
   • Right click on the desired unit and select "Properties".
   • Navigate to the "Shadow Copy" tab.

2. Shadow copy configuration:

   • You can activate the option of "Create Copies of Shadow".
   • Configure the amount of space that can be assigned to shadow copies.

3. Manual Creation of Copies of Shadow:

   • In the same tab, The user can create copies of shadow manually at any time.

Use of Shadow Copy in file restoration

One of the main advantages of Shadow Copy is the ability to restore previous archives and folders versions. To restore a file:

1. Right click on the desired file or folder.
2. Select "Properties".
3. Navigate to the "previous versions" tab ".
4. Choose the version that you want to restore and follow the instructions to restore the file.

Limitations and considerations

Space limitations

One of the main challenges associated with shadow copies is disk space limitation. Although VSS avoids the duplication of data by storing only the differences in incremental copies, The ability of the disk can be filled quickly in volumes with many changes. Therefore, It is crucial to monitor the use of space and adjust the shade copy configurations as necessary.

Application compatibility

Not all applications are compatible with vss. Some applications may not have implemented VSS writers, what can result in inconsistent shadow copies. It is essential to verify the compatibility of critical applications before depending on vss for the creation of backups.

System performance

During the process of creating a copy of shadow, There may be a slight degradation of system performance, especially if intensive disk operations are being carried out. It is advisable to program the creation of shadow copies in periods of low activity to minimize the impact.

Best practices for the use of Shadow Copy

1. Regular programming: Establishing regular schedules for the creation of shadow copies can help protect critical data and reduce the loss of information in case of failures.

2. Disk space monitoring: Regularly supervise the use of shade copies space and adjust the configurations to prevent storage.

3. Use of third -party tools: For critical applications, Consider the implementation of third -party backup solutions that are compatible with VSS to maximize data integrity.

4. Restoration tests: Perform periodic file restoration tests from shadow copies to ensure that the process works correctly when necessary.

Conclution

Windows Shadow copy's function is a powerful tool for the management of backups and data recovery. With its architecture designed to minimize the interruption of access to data and their ability to create coherent copies even when the files are in use, It is a valuable solution for professionals and system administrators. However, Its implementation requires a clear understanding of its limitations and best practices to maximize its effectiveness. With due planning and consideration, VSS can be a key component in the strategy of data protectionData protection refers to the measures and regulations implemented to safeguard the personal information of individuals. In an increasingly digital world, Proper data management is crucial to prevent misuse and ensure privacy. The most notable regulation in this area is the General Data Protection Regulation (GDPR) of the European Union, that establishes rights and obligations for.... of any organization.