Updates from QA Training

Restoring Data From a Shadow Copy

You use shadow copies to restore previous versions of files and folders. It is much faster to restore a previous version of a file from a shadow copy than from a traditional backup copy, which might be stored offsite. Files and folders can be recovered by administrators, or directly by end users.


Bryan O'Connor | 21 April 2013

You use shadow copies to restore previous versions of files and folders. It is much faster to restore a previous version of a file from a shadow copy than from a traditional backup copy, which might be stored offsite. Files and folders can be recovered by administrators, or directly by end users.

One of the courses I teach is the Microsoft Windows 2012 Installing and Configuring course, the Microsoft designation is the 20410B .

In the presentation, we look at restoring data from a Shadow Copy.

A shadow copy is a static image (or a snapshot) of a set of data, such as a file or folder. Shadow copies provide the capability to recover files and folders based on snapshots that are taken of storage drives. After a snapshot is taken, you can view and potentially restore previous versions of files and folders that existed at the time that the snapshot was taken.

A shadow copy does not make a complete copy of all files for each snapshot. Instead, after a snapshot is taken, Windows Server 2012 tracks changes to the drive. A specific amount of disk space is allocated for tracking the changed disk blocks. When you access a previous version of a file, some of the content might be in the current version of the file, and some might be in the snapshot.

By default, the changed disk blocks are stored on the same drive as the original file, but you can modify this behaviour. You can also define how much disk space is allocated for shadow copies. Multiple snapshots are retained until the allocated disk space is full, after which, older snapshots are removed to make room for new snapshots. The amount of disk space that is used by a snapshot is based on the size of disk changes between snapshots.

Because a snapshot is not a complete copy of files, you cannot use shadow copies as a replacement for traditional backups. If the disk containing a drive is lost or damaged, then the snapshots of that drive are also lost.

Shadow copies are suitable for recovering data files, but not for more complex data (such as databases), that need to be logically consistent before a backup is performed. A database that is restored from previous versions is likely to be corrupt and require database repairs.

The demonstration is available at the BryanQA Youtube site

Bryan O'Connor

Senior Technical Instructor

Bryan O’Connor is a Senior Technical Instructor at QA, teaching VMware, Microsoft and CompTIA courses. In the past, Bryan has also been certified by Novell as a MCNI (Master Certified Novell Instructor). Bryan started in the world of IT in 1986 and has worked in a variety of roles ranging from PC support technician to Network design and consultancy, to Virtualisation consultant. At last count, Bryan held over 40 professional VMware, Microsoft, Novell and CompTIA certifications. Bryan has advised many large organisations on their IT and project management needs to allow them to benefit from the increase in productivity provided by computer systems. In addition to teaching, Bryan does a variety of jobs in QA, including supporting the sales staff and setting up the classrooms. Outside of QA, Bryan enjoys spending time with his wife Tracey and their two daughters Meagan and Jessica, unless there’s a grand prix on the TV when he enjoys paying Tracey, Meagan and Jessica to disappear for the day.
Talk to our learning experts

Talk to our team of learning experts

Every business has different learning needs. QA has over 30 years of experience in combining the highest quality training with the most comprehensive range of learning services, ensuring the very best fit for your organisation.

Get in touch with our learning experts to talk about how we can help.