Shadow copies can only be created on NTFS volumes to create automatic backups of files or data per volume. When enabled, the Shadow copies feature protects you from accidentally losing important files in a network share.
Remember that when users delete files from over the network, those files are permanently deleted. Because shadow copies enable users to view previous versions of files, the feature allows them to restore a backup of deleted files. If volume shadow copies are enabled for shared folders, you can restore or recover files which have been accidentally deleted or which have become corrupt. The prior versions of files can be copied to the same location, or to another location.
Through volume shadow copies, you can recover files which have been overwritten when you need to use a previous version of the file. Volume shadow copies also enable you to compare changes between a current version of the file and a previous version of the file. The integrity of the previous file versions are maintained because they are read-only copies, thereby preventing any user from changing a file which was shadow copied.
If users need to change a previous version of a file, they have to copy the version to a different location, and then perform the necessary changes. As mentioned previously, you can only configure volume shadow copies on NTFS volumes. Shadow copies are used to create shadowed copies of files, at a specified point in time and on a per volume basis, which means that you basically configure shadow copies at the volume level.
You cannot therefore specify only certain files and folders for volume shadow copies. The NTFS volume that you want to configure for volume shadow copies must have MB of free volume space minimum requirement. Each volume enabled for shadow copies can only store 64 shadow copies. When this limit is reached on a volume, the oldest shadow copy is permanently deleted, and cannot be restored. You can therefore only view a maximum of 64 previous versions of files.
Shadow copies should not be utilized to replace performing regular backups, but should be used to enhance the backup strategy of your organization. For clients to access shadow copies, they need to have the Previous Versions Client software installed. The software can be distributed or deployed via Group Policy, Systems Management Server SMS , or you can create a share so that clients can download the necessary software.
You can enable shadow copies through the Computer Management console which can be accessed through the Administrative Tools folder.
Shadow copies are enabled from the Shared Folders folder in the left pane of the Computer Management console. To navigate to the Shared Folders folder, expand System Tools. This is the location where you manage and configure the volume shadow copies feature. You seem to have only a little space left as it is, enabling shadow copies will eat that space up, and you are introducing an external drive that could fail not the drive but the USB portion causing VSS corruption.
Don't get me wrong, I'm not saying that Shadow Copies are bad and you should not use them, I'm just trying to impress upon you to be sure you understand their function properly and know some of the gotchas before they bite you in a time of need. No, it's not a backup replacement and neither is DFS, but I try to use both as supplements to my backup solutions and they do fall into a data protection solution.
But the most important part of that data protection is the true backup of the server. To continue this discussion, please ask a new question. Get answers from your peers along with millions of IT pros who visit Spiceworks.
Hi All, I have a drive with 1. I would like to enable shadow copy, but i am afraid that the disk becomes full. Are there some calculation to do before enable shadow copy?
Are the some best practices? Thank you. Best Answer. Thai Pepper. Select Configure Shadow Copies Click on the Volume you want to enable Shadow Copies for, then click Settings. Under Storage Area , change the location to the additional disk you created in the Prerequisite Steps section of this document. You can also change the size limit of the volume copies. If this storage limit is reached, it will automatically delete the oldest copy.
The Schedule button allows you to set a preferred schedule to capture the Shadow Copies. This means that some of the data files might be open or they might be in an inconsistent state. Correctly performing backup and restore operations requires close coordination between the backup applications, the line-of-business applications that are being backed up, and the storage management hardware and software.
When all the components support VSS, you can use them to back up your application data without taking the applications offline. VSS coordinates the actions that are required to create a consistent shadow copy also known as a snapshot or a point-in-time copy of the data that is to be backed up. The shadow copy can be used as-is, or it can be used in scenarios such as the following:.
You want to back up application data and system state information, including archiving data to another hard disk drive, to tape, or to other removable media. VSS service Part of the Windows operating system that ensures the other components can communicate with each other properly and work together. VSS requester The software that requests the actual creation of shadow copies or other high-level operations like importing or deleting them.
Typically, this is the backup application. VSS writer The component that guarantees we have a consistent data set to back up. VSS writers for various Windows components, such as the registry, are included with the Windows operating system.
Non-Microsoft VSS writers are included with many applications for Windows that need to guarantee data consistency during back up. VSS provider The component that creates and maintains the shadow copies. This can occur in the software or in the hardware. The Windows operating system includes a VSS provider that uses copy-on-write.
A hardware provider offloads the task of creating and maintaining a shadow copy from the host operating system. The following diagram illustrates how the VSS service coordinates with requesters, writers, and providers to create a shadow copy of a volume. This section puts the various roles of the requester, writer, and provider into context by listing the steps that need to be taken to create a shadow copy.
The following diagram shows how the Volume Shadow Copy Service controls the overall coordination of the requester, writer, and provider. The requester asks the Volume Shadow Copy Service to enumerate the writers, gather the writer metadata, and prepare for shadow copy creation. Each writer creates an XML description of the components and data stores that need to be backed up and provides it to the Volume Shadow Copy Service. The writer also defines a restore method, which is used for all components.
The Volume Shadow Copy Service provides the writer's description to the requester, which selects the components that will be backed up. The Volume Shadow Copy Service notifies all the writers to prepare their data for making a shadow copy. Each writer prepares the data as appropriate, such as completing all open transactions, rolling transaction logs, and flushing caches. When the data is ready to be shadow-copied, the writer notifies the Volume Shadow Copy Service. The application freeze is not allowed to take longer than 60 seconds.
The Volume Shadow Copy Service flushes the file system buffers and then freezes the file system, which ensures that the file system metadata is recorded correctly and the data to be shadow-copied is written in a consistent order. The Volume Shadow Copy Service tells the provider to create the shadow copy. At this point applications are free to resume writing data to the disk that is being shadow-copied.
The shadow copy creation can be aborted if the writers are kept in the freeze state for longer than 60 seconds or if the providers take longer than 10 seconds to commit the shadow copy. The requester can retry the process go back to step 1 or notify the administrator to retry at a later time.
If the shadow copy is successfully created, the Volume Shadow Copy Service returns the location information for the shadow copy to the requester. In some cases, the shadow copy can be temporarily made available as a read-write volume so that VSS and one or more applications can alter the contents of the shadow copy before the shadow copy is finished. After VSS and the applications make their alterations, the shadow copy is made read-only.
This phase is called Auto-recovery, and it is used to undo any file-system or application transactions on the shadow copy volume that were not completed before the shadow copy was created. A hardware or software shadow copy provider uses one of the following methods for creating a shadow copy:.
Complete copy This method makes a complete copy called a "full copy" or "clone" of the original volume at a given point in time. This copy is read-only. Copy-on-write This method does not copy the original volume. Redirect-on-write This method does not copy the original volume, and it does not make any changes to the original volume after a given point in time.
Instead, it makes a differential copy by redirecting all changes to a different volume. After the mirror connection is broken, the original volume and the shadow copy volume are independent.
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