Guidelines to configure Stubbing policy for SharePoint Online
The SharePoint Online connector can be configured with a policy to perform stubbing. Stubbing helps to reduce storage in the SharePoint Online environment. When enabled, during the backup process, backed up items are changed to stubs (shortcuts) and original item versions are deleted. Stubs appear in SharePoint as URL files ending in the .stub.url extension. By clicking on the stub an end-user can either download the data from Cohesity Alta SaaS Protection locally or restore the stubbed items back to its original location in the SharePoint site (this behavior is configurable by an Cohesity Alta SaaS Protection administrator).
Cohesity Alta SaaS Protection supports archiving and stubbing for the following workloads:
SharePoint Online
Team Sites
OneDrive
The stubbing policy can be customized based on the following criteria:
You can define any or all of these criteria according to your specific data retention requirements.
It's advisable to first test the impact of your stubbing policy in a small or less frequently used environment before rolling it out widely. This will help administrators and end-users become familiar with how stubbed files behave. It's important to note that stubbed files do not directly replace the original file in terms of supporting the same functionality within SharePoint.
Review the section to understand the implications of configuring stubbing and can select Sites and Locations eligible for stubbing, with the appropriate stubbing policy.
Determine whether you plan to use Cohesity Alta SaaS Protection only to stub certain SharePoint/OneDrive items based on policy, or to back up all data in SharePoint Sites/OneDrive while also stubbing certain items.
If you plan for only stubbing, ensure that your Custom Backup Policy and Stubbing Policy align with each other.
To achieve savings sooner, target larger items first (for example, items > 5 MB, with last modified > 1 year, or whatever your date criteria may be).
Later, adjust the criteria for both the Custom Backup Policy and Stubbing Policy to what you plan to use on an ongoing basis (for example, items > 1 MB with last modified > 1 year).
If stubbing items based on policy while also backing up all items, follow the guidelines in step 2. When setting the ongoing criteria, clear the settings in the so that all items are included in the backup, but only items meeting the stubbing policy criteria are eligible for stubbing.
As the stubbing process deletes data at the source and replaces it with URLs, it is important to understand the implications of the Cohesity Alta SaaS Protection process before enabling the stubbing policy. Cohesity cannot help or support the customer if they exercise or run into unsupported scenarios. It will be the customer's responsibility to recover from the situation.
Cohesity Alta SaaS Protection stubs an item after the data is moved to Cohesity Alta SaaS Protection storage, depending on the options configured in the connector and its backup policies. By default, Cohesity Alta SaaS Protection does not maintain any other copies of the item. Therefore, Cohesity Alta SaaS Protection stubs items only after creating a primary backup copy. Care should be taken to ensure that this primary copy is not deleted, for example, due to a misconfigured Cohesity Alta SaaS Protection deletion policy.
Additional options, such as Extra Data Backup, need to be purchased if you want Cohesity Alta SaaS Protection to maintain a separate secondary copy.
Only a file can be stubbed. A folder, library or a site cannot be stubbed.
There may be automated processes within SharePoint Online or third-party software integrated with SharePoint Online that rely on the actual file being present to achieve certain objectives/workflow within site collections, for example, Akumina. Such functionality can be disrupted because of Cohesity Alta SaaS Protection stubbing. Such locations should be excluded from stubbing manually.
There may also be automated processes within SharePoint Online or by the third-party software that copy, move, or create libraries and folders where potentially stubbed files can reside. These locations should also be excluded from stubbing manually.
If stubbing is based on the 'last modified' date, note that the content, which is frequently accessed but not modified will still be stubbed. Careful consideration should be given to whether such content should be stubbed, as keeping it as stubs may not be desired and can lead to frequent requests to restore the original content.
For the above reasons, it is crucial to thoroughly evaluate what should not be stubbed before initiating the stubbing process. This careful planning ensures that the stubbing policies are configured correctly, preventing any inadvertent issues.
If sites or libraries are accidentally stubbed, administrators will have to resort to doing restores by the admin portal. Depending on the number of sites and lists, the need for mass un-stubbing restores may arise. This can take time and may result in a diminished end-user experience.
Considerations for the restores when stub policy is based on 'Last modified time'. When doing restores, if the stub recall options have:
Restore: When content is recalled by clicking on the stub, Cohesity Alta SaaS Protection updates the modification time to prevent the item from being stubbed again immediately.
Download Only: End users can download the file, but restores can only be performed from the Administration Portal. By default, when restoring from the Administration Portal, the original last modified time is restored, meaning that the restored content can be stubbed again. To prevent this:
Exclude the content from stubbing after it has been restored.
When restoring from the Admin Portal, select the option Reset 'last modified time' of restored items to time of restore.
Stubbing is not supported for Project Web Access sites. These sites must be manually excluded from the stubbing policy.
Interaction of Cohesity Alta SaaS Protection stubbing in sites with the SPO features like, DLP, SharePoint Workflows is not supported. Sites with these functionalities should be excluded from stubbing manually.
This section describes the behavior of a stub and its corresponding item in Cohesity Alta SaaS Protection under specific scenarios as follows:
If a stub is deleted, Cohesity Alta SaaS Protection marks the corresponding item as in Cohesity Alta SaaS Protection storage during the next backup cycle.
Note:
indicates that Cohesity Alta SaaS Protection recognizes the item is no longer present in its original location. This is important as Cohesity Alta SaaS Protection deletion policies are often configured to delete items marked as .
When the stub is restored to its original location from the Recycle Bin, in Cohesity Alta SaaS Protection's next scan the flag will be cleared, and access permissions (in Cohesity Alta SaaS Protection) will be updated based on existing permissions on source item.
If an end-user copies or moves stub in SharePoint Online, Cohesity Alta SaaS Protection backup scans detect the change and perform the following:
Copies the original item backed up in Cohesity Alta SaaS Protection to a corresponding new location in Cohesity Alta SaaS Protection and sets an .
Modifies the stubs in the destination SPO location to point to the newly copied item in Cohesity Alta SaaS Protection. Same is now referred to during the item restore or download.
The of the stub item is labeled as , , or based on the detected action as describe in the following table.
Scenario
Behavior
Archival method type
Stub is moved
The original item along with all its versions are copied to the new location in Cohesity Alta SaaS Protection.
Moved stub
Stub is copied
Only the latest version of the original item is copied to the new location in Cohesity Alta SaaS Protection.
Copied stub
The action (move or copy) is undetermined. This behavior can be observed when stubs are moved across sites. Some scenarios in which Cohesity Alta SaaS Protection cannot detect whether a stub was moved or copied in SharePoint. It includes the following:
The stub is copied from a library without versioning to another library (with or without versioning).
The stub is moved to a library with versioning, and then its properties are changed in SharePoint.
Cohesity Alta SaaS Protection treats it as a move and copies the item.
Moved or copied
The of an item in Cohesity Alta SaaS Protection is fixed once set. It does not change after the stub is restored.
Each time a stub is moved or copied, a copy of the item is created in Cohesity Alta SaaS Protection. This copy counts toward the licensed storage used by Cohesity Alta SaaS Protection.
If the stub copy or move operation fails to update the stub in SharePoint (for example, due to SharePoint restrictions), users may experience the behaviors described in points a and b below when accessing the stub from SharePoint. In such cases, the Administration portal can be used to access or restore the items directly from Cohesity Alta SaaS Protection.
If copied or moved stubs are not detected during incremental backups, Cohesity Alta SaaS Protection will process them during the next full backup scan.
For moved stubs in SharePoint Online, the original item in Cohesity Alta SaaS Protection will be marked as only during full backup scans.
The flag will not be carried over to the versions of the copied item.
If an end-user tries to restore or download items from a copied or moved stub in SharePoint before the item is copied to the new location in Cohesity Alta SaaS Protection, the following may occur:
The user may see an Access Denied error if they don't have permission to access the original item in Cohesity Alta SaaS Protection.
If the user does have permission to the original item and tries to restore it:
(a). The file will be restored to the original location.
(b). The copied or moved stub in SharePoint remains unchanged.
If the restore is executed from the Administration portal with the option, before the item is copied to the new location in Cohesity Alta SaaS Protection, stubbed files may not be restored at the destination in SharePoint where they were moved or copied.
In SharePoint, if a retention label is applied to a copied or moved stub at the destination, Cohesity Alta SaaS Protection will not delete the existing version of the stub in SharePoint after updating it.
If a stub is copied or moved to a library with moderation, minor versioning, or required checkout enabled, the field of the stub in SharePoint will be set to during the copy operation.
The copied items, in Cohesity Alta SaaS Protection, do not retain the Cohesity Alta SaaS Protection policies, legal holds, or retention settings applied to the original items. They are treated as newly backed-up items, and Cohesity Alta SaaS Protection applies policies based on the current configuration.
The time for copied items in Cohesity Alta SaaS Protection reflects the time the copy operation occurred.
Newly copied items in Cohesity Alta SaaS Protection will have the same access permissions from the stub at the destination in SharePoint Online.
If the copy operation within Cohesity Alta SaaS Protection fails, a flag will be set on the source item in Cohesity Alta SaaS Protection, along with the pending destination path. Items marked as will be excluded from deletion when Cohesity Alta SaaS Protection deletion policies are run.
If the stub copy operation fails, Cohesity Alta SaaS Protection will retry it during the next full backup scan. The copy pending path will be cleared after the item is successfully copied. The flag will be removed only after all pending copies are completed.
Cohesity Alta SaaS Protection needs to scan the destination location in SharePoint Online to perform the copy. Therefore, you may notice a delay before the copied stub appears in Cohesity Alta SaaS Protection, as it depends on the backup task copying the data and updating the stub.
Backup task statistics will show details such as the number of updated stubs and the size of the copied data.
Cohesity Alta SaaS Protection cannot copy an item if the original item is deleted from Cohesity Alta SaaS Protection before the backup task performs the copy. It is the user's responsibility to configure the Cohesity Alta SaaS Protection Deletion Policy properly, ensuring backup tasks have enough time to detect and process copied or moved stubs.
Example: If a deleted stub in SharePoint is restored from the Recycle Bin after the corresponding item has already been deleted from Cohesity Alta SaaS Protection, the item cannot be copied, and the user will encounter copy errors for that stub.
If a moved stub is detected to have returned to its original location in SharePoint (as known to Cohesity Alta SaaS Protection), only the flag will be cleared, and access permissions (in Cohesity Alta SaaS Protection) will be updated based on existing permissions on source item.
When a stub is copied or moved across libraries, any columns in the source library that do not exist in the destination library cannot be restored.
If a stub at a copy-pending path is deleted in SharePoint before Cohesity Alta SaaS Protection can copy the item, the copy pending path will remain on the source item in Cohesity Alta SaaS Protection. If Cohesity Alta SaaS Protection Deletion Policy does not remove such items, please contact support.
It is not supported to configure the same site for stubbing in multiple connectors. Cohesity Alta SaaS Protection will not copy stubbed items from the same site across different connectors by default. A warning message will appear in the logs in such cases. Support should be contacted for guidance on next steps.
Cohesity Alta SaaS Protection does not support copying items across different Cohesity Alta SaaS Protection tenants.
Backup tasks may take longer to complete if there are many stub move or copy operations in SharePoint that require item copying in Cohesity Alta SaaS Protection.
Once the feature is enabled, the backup task will attempt to retroactively correct any previously copied or moved stubs in SharePoint. If the destination SharePoint site, where stub is moved or copied cannot be configured for backup in Cohesity Alta SaaS Protection, then stub access/restore from the SharePoint site may not work.
For more details, refer to the knowledge base article: Issues when accessing or restoring files from copied or moved stubs (.stub.url) in SharePoint Online.
Cohesity Alta SaaS Protection does not support renaming .stub.url files. Renaming .stub.url files may cause issues when restoring the item from Cohesity Alta SaaS Protection.
If the versioning setting of a Document Library in SharePoint is changed from 'Create Major/Minor Version' to 'No Versioning' or vice versa, during the next backup cycle, the corresponding item in Cohesity Alta SaaS Protection is marked as .
If an item in Cohesity Alta SaaS Protection storage qualifies for a Cohesity Alta SaaS Protection deletion policy for deletion, it will be deleted from storage without verifying whether it is stubbed at the source.
The property can also be used a criterion for Cohesity Alta SaaS Protection deletion policies. This means that deletion policies can remove items marked as in Cohesity Alta SaaS Protection, even if they are still present at the source (due to certain scenarios described above for example the stub is moved and the location is yet to be scanned by Cohesity Alta SaaS Protection detect the change).
Recommendation: It is strongly recommended not to use Cohesity Alta SaaS Protection deletion policies that target content where stubbing is or was enabled at the source.
For a site being backed up by a connector with a stubbing policy, and that contains stubbed items which have been stubbed by same connector, the stubs should be restored before removing the site from the connector or deleting the connector.
For a site being backed up by a connector with a stubbing policy, if the same site is added to a new connector, no data will be backed up for the data that was stubbed the previous connector by the new connector.
Stubbing same site by multiple connector is not supported.
When an item is stubbed, its permissions are not changed. Any changes to the permissions after the item is stubbed are captured by Cohesity Alta SaaS Protection.
When a stub is restored back to a file by Cohesity Alta SaaS Protection, the permissions the stub had prior to the restore are maintained by default.
Cohesity Alta SaaS Protection only allows access to files for end-users with the specific SharePoint Permission Levels which contain the Open List Items permission. If a user or group only has SharePoint Permission Levels which contain View Items or View Application Pages permissions, Cohesity Alta SaaS Protection will not permit access to those files. Default SharePoint permission levels that use the View Items permission include Restricted View, View Only, and Download Only. By default such files are not stubbed. When files are stubbed, users with these permission levels will not be able to access the files from the stub.
For more details on how Cohesity Alta SaaS Protection syncs end-user permissions, refer to the section Cohesity Alta SaaS Protection.
If Cohesity Alta SaaS Protection backs up and stubs SharePoint sites in two different AD tenants with shared users (for example, a user in Tenant A is also an external user in Tenant B), issues can arise for the shared user if they try to access an item in Cohesity Alta SaaS Protection, via its SharePoint stub in a site present in a tenant where that user is a external. Such a configuration should be avoided.
When an item is stubbed, its properties and permissions are preserved.
Any changes to properties made after the item is stubbed are not captured by Cohesity Alta SaaS Protection.
When a stub is restored back to a file by Cohesity Alta SaaS Protection, the list column properties are restored to the state they were in when Cohesity Alta SaaS Protection initially backed up the item.
When configuring exclusions based on type, you must also configure either the last modified date or size criteria.
The connector stubbing policy will consider an item for stubbing only if all its captured versions meet the criteria configured in the policy.
The stubbing policy is applied starting from the second full backup, after all data has been successfully backed up during the first full backup.
The connector stubbing policy applies only to full backups and does not apply to incremental backups occurring between two full backups.
If both the connector deletion and connector stubbing policies target the same item, the delete policy takes precedence and permanently deletes the item from the source SharePoint environment.
The stubbing policy applies exclusively to files within document libraries and not to any other library types.
The stubbing policy specifically applies to items derived from the Document SharePoint content type.
ASPX files
Links with a .url extension
Document libraries in SharePoint that have the setting enabled.
Some site templates, like Publishing Site, create document libraries with this setting enabled. As a result, items in these libraries cannot be stubbed.
Contact Cohesity Support to enable stubbing for these items.
Files in libraries and lists with the Information Rights Management (IRM) setting enabled.
Items that are checked out.
Thicket file.
Starting from the 2.26.1 release, the following items cannot be stubbed using the Stubbing policy:
All items in sites, which are on legal hold or have a retention policy.
You need to contact Cohesity Support to enable stubbing for these items.
Only when Legal Holds done through Microsoft Purview by link Create eDiscovery holds in an eDiscovery case Microsoft Learn, Cohesity Alta SaaS Protection can detect, and skip stubbing for such items. Any other way is unsupported. Legal holds applied through any other way are unsupported, as a result Cohesity Alta SaaS Protection's stubbing process will not be able to detect legal holds and continue to stub the items in the site and may result in unsupported behavior (for example, items may appear as a stub but versions may still remain in SharePoint).
Contact Cohesity support team to stub other items in such sites.
Starting from the 2.28.1 release, the following items cannot be stubbed:
Items with a sensitivity label configured for encryption cannot be stubbed.
Items in read-only sites.
Items marked with a retention label and still within the retention period.
Starting from the 2.31.1 release, the following items cannot be stubbed:
Items in lists and libraries with the following version settings enabled in SharePoint Online:
Require content approval for submitted items.
Create major and minor (draft) versions (for example, 1.0, 1.1, 1.2, 2.0)
Some site templates, like Publishing Site, create document libraries with these settings, preventing stubbing in such libraries for the site.
Cohesity Alta SaaS Protection does not support the stubbing of Loop components in emails and Teams chats.
For more information on Loop components, refer to the Microsoft knowledge base article: Overview of Loop Components in Microsoft 365.
Starting from the 2.35.1 release, the items/files with permission will not be stubbed.
OneNote notebooks.
Sharing links (by Teams, OneDrive, or SharePoint) for items created before and after stubbing may not work.
Accessing stubs through the Microsoft SharePoint App on iOS and Android is not supported. Users can open the SharePoint site in Safari or Chrome, navigate to the library containing the stub, and click on it to access the data in Cohesity Alta SaaS Protection.
When files synchronized with laptops or PCs using the OneDrive client are stubbed, Cohesity Alta SaaS Protection replaces the items with internet shortcuts, adding the .stub.url extension to the item name.
When an end user tries to access the stubbed file from File Explorer, they are navigated to a browser. Based on the settings configured in Cohesity Alta SaaS Protection for managing end-user experiences with stubs, appropriate actions will be taken. Refer to the section for more details.
When stubbing a file the OneDrive Sync client may add or/and change the stub file. Cohesity does not support the scenario, if the change disrupts the functioning of the stub.
Errors can occur at any stage of the stubbing process. The stubbing process attempts to recover from errors by either keeping the original file intact as much as possible or fully stubbing the item.
For more information on how to handle these errors, refer to the tech note: Cohesity Alta SaaS Protection: Microsoft SharePoint Online Item Stubbing Errors.
The following browsers are supported for accessing data in Cohesity Alta SaaS Protection by a stub:
Browser
Restore and Download stub
Download only
Chrome
Supported
Supported
Edge
Supported
Supported
Safari
Not supported
Supported
If there are any external modifications to the stub by any processes other than Cohesity Alta SaaS Protection, this may lead to unsupported scenarios - for example, external processes like a different backup vendor, SharePoint workflows.
See Run the Delete and Stubbing policies to the SharePoint Online environment.
A Cohesity Alta SaaS Protection stub in SharePoint is orphaned when the data that it refers to in the backup storage is deleted from Cohesity Alta SaaS Protection. This can happen due to Cohesity Alta SaaS Protection deletion policies running in Cohesity Alta SaaS Protection or through a manual deletion action from Cohesity Alta SaaS Protection. There is an option to clean up such stubs from SharePoint sites. This cleanup happens during a backup task. This is disabled by default. You can contact support to enable this feature. When enabled, this happens every 15 days, this interval can be changed.
Orphan stub deletion is only performed during full backup tasks and not in incremental tasks.
For a stub created for a file in a SharePoint versioned library, a stub is considered as orphan only if all versions in backup storage have been deleted from Cohesity Alta SaaS Protection. Note that SharePoint versions present in Cohesity Alta SaaS Protection but marked as are also considered in the above check. So, if all available versions in Cohesity Alta SaaS Protection backup are marked as , the functionality will consider the stub as orphan and delete it from Site.
For more information on the end-user workflow when an end-user clicks on a stub, refer to the topic Restore OneDrive/SharePoint stubbed items in the Cohesity Alta SaaS Protection End User Guide.
As an administrator, you can control the options available to the end-user. You can direct them to the End-User portal to restore the specific item or initiate the download when a stub is clicked. You can use the following permissions to manage the experience of the end user in restoring or downloading the stubbed items:
: With this permission, when an end-user clicks on the stubbed item, they are redirected to a webpage. On this webpage, an option is available to restore the item to its original location at the time of backup.
: With this permission, when an end-user clicks on the stubbed item, they are redirected to a webpage. On this webpage, an option is available to download the last backed-up version of the SharePoint file to the local computer.
If only this permission is assigned, the download starts when the user clicks the stub.
Both of these permissions are inherently included in the role.
You can monitor the restore progress on the .
A SharePoint user with the View permission can restore the file. The user retains the same permissions for the file after restoration as they had on the stub.
If an end-user tries to restore or download items from a copied or moved stub in SharePoint before the item is copied to the new location in Cohesity Alta SaaS Protection, the restore operation may fail. for more details, refer to the Stub movement section.
The last modified date is updated to the current time after restoration or download. This should prevent the item from being picked up by the configured Stub policy if configured based on the last modified time.
Only the last backed-up version of the SharePoint item before the stubbing occurred is restored.
When an end-user performs a restore to unstub an item, only the latest version is restored. All other versions are marked as 'Removed from source' during the next backup.
You can monitor the restore progress on the Restore dashboard, but you cannot rerun the restore.
If your tenant is Scope enabled, then clicking on a stub always download the last backed-up version of the SharePoint file to the local computer.