Migrations between different sources and targets often have incompatability issues due different capabilites,limitations and behaviours in the target which could impact the migration.

The Pre-check option allows  a set of checks against the source data to be executed, based upon the known limits of SharePoint.  Each can be enabled/disabled and some have additional configuration parameters which can be customised as required.

NOTE: Migrations will still be attempted for items that are reported as potentials issues in the Pre-check.  This is why it’s important to review and correct as necessary to ensure the successful migration of items.

NOTE: The nature of pre-checks means that if Discovery is halted before completion then pre-check results may be inconsitent and cannot be relied upon.

 

 

6.4.1.  Changing Pre-Check Settings

The ‘Change Settings’ option displays the options below and allows the checks to be enabled/disabled as well as specifying any relevant values.

Restrictions:

Restrictions are issues that may prevent the folder or file actually being migrated.  So for example, because they contain characters in the filename which the target will not allow.

 

 

Blocked Characters in Filenames:

Description: Checks for illegal characters in Source file/folder.

Impact: Items will be migrated but will contain replacement character as specified in General Settings.

Resolution steps:  Use General Settings to assign a character to replace any invalid characters.

Invalid or Blocked File Types:

Description: Checks if file type of item is on the blocked file types list.  Default list is empty as SharePoint currently supports all File types.

Impact: Items would fail migration but currently N/A.

Resolution steps: Exclude items from migration or convert to supported file type if applicable.

Temporary file Extensions:

Description: Checks for files with specified file type that is considered a temporary file extension and so is likely something that does not require migration.  Use comma separated list to provide multiple file extensions.

Impact: Items would be migrated.

Resolution steps: Contact Technical Support.

 

Limitations

These are limitations in the Target that may prevent the folder/file being migrated.  Unlike restrictions, limitations are those that are only an issue once a value exceeds the defined threshold based upon the limits of the target.

 

 

Max File Size:

Description: Checks whether the file size exceeds the maximum file size for SharePoint/SharePoint Online.

Impact: Items will fail migration.

Resolution steps: Migrate manually or exclude from migration.

Max characters in Filename: 

Description: Checks whether the length of item name exceeds the SharePoint/SharePoint Online limits.

Impact: Items will fail migration.

Resolution steps:  Rename source item or rename during migration by setting up a rule for item name mapping. See Populating Target using Functions where you can use functions to trim fields.

Max characters in Folder Name: 

Description: Checks whether the length of folder name exceeds the SharePoint/SharePoint Online limits.

Impact: Items will fail migration

Resolution steps: Reorganise folders in source, use structure mapping or contact technical support for assistance.

Max URL Length for Items: 

Description: Checks whether the length of a parent container exceeds SharePoint limits.

Impact: Items will fail migration.

Resolution steps: Contact Technical Support.

Max URL Length for Containers:

Description: Checks overall URL length

Impact: Items will fail migration.

Resolution steps: Rename item(s) in source, rename during migration by setting up a rule for item name mapping or shorten the path during migration by using structure mapping.

Maximum Items in Folder:

Description: Checks whether the folder contains more items than permitted within SharePoint Online Document Library folders.

Impact: Items will fail migration once target item limit reached in folder

Resolution steps: This can be resolved either by restructuring data in the source or through structure mapping during migration.

Max Major Versions per Document:

Description: Checks for number of major versions per item since SharePoint has a limit on the number of major versions supported.

Impact: Items will fail migration.

Resolution steps: Contact Technical Support

Max Minor Versions per Major Version:

Description: Checks for number of minor versions per major version since SharePoint has a limit on the number of minor versions supported.

Impact: Items will fail migration.

Resolution steps: Contact Technical Support

Duplication

Any duplication or empty files that may not get migrated into the Target

 

 

Duplicate file names:

Description: Checks if there are items in the source dataset with the same name

NOTE: Unlike other pre-checks, this check can take several hours to run in larger environments.  E.g. 8 hours in an environment of several million items.

Impact: Items will fail migration unless one of the resolution steps below is used.

Resolution steps:  In General Settings, Duplication there is the option “Create a new file with a unique name” to control the migration of duplicate named items and provide a unique name as required (by default this is enabled).  Alternatively, restructuring the source system and rerun discovery or resolve the conflict using structure mapping.

Files with no name:  

Description: Checks whether the Item Name field is blank.    

Impact: Items cannot be migrated

Resolution steps: Edit source item or create a function mapping to assign value. See Populating Target using Functions where you can use functions to apply a name in such scenarios. 

Deleted (or marked for deletion):  

Description: Checks whether the item is marked as deleted in the Source system.

Impact: Items that have been deleted/marked for deletion will still be migrated.

Resolution steps: Contact Technical Support

Empty content (Zero Byte):

Description: Checks whether the Item size is zero bytes as this could indicate issue with the source system

Impact: Items will fail migration.

Resolution steps: Items should be examined by a record officer/system administrator to determine whether the files truly are missing. if so, the issue can be worked around by loading placeholder content using the "LoadPlaceholdersForMissingOrEmptyFiles" advanced setting.

Empty Folders:

Description: Checks for folders with no content.  By default this check is OFF and so not executed.

Impact: Empty folders will be migrated.

Resolution steps: Review the list to see if such folders should be excluded from migration. By default such items will be migrated but the configuration key FilterEmptySourceFolders can be set to True so empty folders are not migrated.

Other Checks

Other properties that may prevent migration into the Target.

 

 

Mismatch File Names across versions:
Description: Checks whether the versioned items having different file names. I.e. version 1 of a file is called Dept Training.docx and version 2 is called Dept Training(Old).docx. In SharePoint, all versions of the file must have the same name.
Impact: Items will be migrated and by default will have the same name as the first version
Resolution steps: For steps on how to use information from the latest version across all versions contact Technical Support
Mismatch File Names or Extensions across versions :
Description: Checks whether the filename or file extension of an items changes across versions of the item. SharePoint requires all names and extensions to be the same for all versions.

Impact: Items will be migrated and by default will have the same name/extension as the first version.

Resolution steps: For steps on how to use information from the latest version across all versions contact Technical Support

Links across Multiple Folders:

Description: Detects if source system has Shortcut links.  In the Power BI report, these are labelled as content referenced by multiple folders.

Impact: Shortcut links need to be migrated if required.

Resolution steps: If Shortcut Links need to be migrated, ensure “Links” source content type is configured correctly in Content Type mapping and run Shortcut Links migration, after all items are successfully migrated.

Content type Mismatch Across Versions:

Description: Checks whether the Content Type/Category/Classification for all versions of a document are the same. Since SharePoint requires all version to be of the same Content Type.

Impact: Items will fail migration.

Resolution steps: Contact Technical support

Unsupported version labels:

Description: SharePoint online supports version labels like 1.1, 2.3 etc.  Some source systems supported version labels such as 2.3.1 or even text label so such issues will be detected with this check.

Impact: Items will fail to migrate

Resolution steps: Contact Technical support

 

6.4.2.  Running Pre-Checks

Select Discovery & Analysis Phase->Pre-Checks option and then select the Start Pre-checks.  The checks normally take several minutes to execute.

 

6.4.3.  Review and correcting pre-check issues

There are two ways to view pre-check results. 

Power BI Report

Once the pre-check is complete, the number of potential issues will be displayed.  Clicking on the ‘View Report’ will launch PowerBI to display the results.  There are several pre-check related tabs which contain the results of each check.  In general, any checks which return a result of ‘True’ are issues to be investigated.

Two warnings are displayed when opening Power BI

1. Potential security risk

Displays warning about ‘Potential security risk’ due to the file using multiple data source. Click OK to continue.

2. Native Database Query

Displays warning to approve running native query.  Click Run

 

PowerBI will open up to display the Content Summary dashboard.  Select the Pre-Check General tab to view the total number of issues.

 

 

The result may be highlighted in amber to suggest a Informational/Warning as opposed to a failure.  An example of this is the ‘Empty Folders’ warning.

 

 

 

In this example of an error, 17 items have file extensions not allowed in the target

Pre-Check Report

There is a pre-check report available and a drop down list of issues and the number of items impacted will be displayed.