Scalable Solutions For Migrating Large Sharepoint Libraries

The Challenge of Moving Terabytes of Data

Migrating extremely large SharePoint libraries with millions of files can be challenging due to difficulties like bandwidth constraints, failed transfers, and metadata loss. As SharePoint farms grow to contain terabytes of documents, images, videos, and other files, companies can struggle to efficiently move these massive libraries to new SharePoint environments or alternative platforms.

Bandwidth limitations are a prime obstacle when dealing with libraries containing hundreds of gigabytes or terabytes of data. Copying so much content across networks, firewalls, and the Internet is time-consuming even on high-speed connections. Companies may not have sufficient outbound bandwidth available on their corporate networks to handle such large-scale data migrations at acceptable speeds.

The sheer quantity of items in gigantic SharePoint libraries also increases the likelihood of failed migration jobs and content transfers timing out before completion. Most migration tools lack native capabilities to gracefully resume broken data transfers. This can corrupt migrated data and necessitate restarting entire jobs when even a small percentage of content fails to copy correctly.

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Additionally, companies with custom SharePoint metadata schemas defined in large libraries can lose this vital metadata if migration utilities do not preserve column definitions and properly extract metadata values from source libraries during copy operations. Manufacturers, engineering firms, oil and gas companies, and others with advanced document management needs depend on robust libraries with deeply descriptive metadata to organize their digital assets and files for discovery and re-use later.

Optimization Strategies to Accelerate Data Transfers

IT administrators can employ a range of optimization strategies to help accelerate and streamline large-scale SharePoint data transfers, including:

Enabling differential migration capabilities to only copy new or changed documents since previous migration jobs.
Configuring throttling rules to avoid overloading target SharePoint farms or bandwidth constraints.
Specifying detailed metadata mappings to automatically preserve column values between environments.

Differential Migration to Limit Unnecessary Data Movement

Transferring only new or altered documents since the last migration operation can dramatically reduce data movement demands when dealing with dynamic SharePoint libraries. As users add, modify, and delete existing items over time in large, live document repositories, propagating just incremental changes to target platforms slashes unnecessary content transfers.

For example, instead of completely re-copying a 1 terabyte SharePoint library overnight, a differential migration may only need to transfer 10 or 20 gigabytes of files that are new or edited within the recent 24 hour period. This approach concentrates computing and bandwidth usage on propagating the most recent shifts in active data.

Configuring Throttling Policies to Control Transfer Speeds

Uncontrolled data migrations can easily overwhelm target SharePoint farms and cloud storage environments. Establishing throttling policies places limits on how fast migration tools push content to destinations, avoiding disruptive bandwidth saturation:

Apply custom throttling rules around maximum transfer speeds in Megabits per second.
Configure throttling to only perform migration batches during specified time windows like evenings or weekends.
Consider allowing throttling policies to dynamically adjust transfer speeds based on target farm workloads.

Retaining Metadata with Column Mappings

To retain crucial metadata from large SharePoint libraries, administrators can create column mappings that pair custom columns from the source to equivalent columns in the destination farm. This metadata mapping should define:

The internal name and data type of each source column.
The corresponding destination column to store values within.

Proper metadata preservation strategies prevent the loss of embedded custom metadata enabling users to efficiently discover, report on, and reuse valuable enterprise documents migrated into new SharePoint platforms.

Leveraging Partitioned Migration for Large-Scale Moves

Partitioning gigantic SharePoint document libraries into smaller segments enables more manageable migration batches that are load-balanced over longer time periods, reducing risk and improving migration success rates.

Breaking Down Massive Libraries into Logical Partitions

Development teams can subdivide monolithic SharePoint data sets along logical boundaries into smaller partitions for migration, including by:

Department or organizational division.
Content type or file category.
Custom metadata values or columns.
Age of documents.

For example, a multi-TB cross-departmental research library could have partitions created for individual labs, project teams, research years, or report types to split the migration workload over weeks or months.

Parallelizing Transfer Batches Across Partitions

Transferring partitions individually simplifies migrations by allowing IT administrators to:

Accelerate partition batches independently based on priority.
Restart failed partition transfers without impacting other completed partitions.
Spread partition migrations over multiple evenings/weekends to reduce business disruption.

If throughput problems emerge on a partition transfer, data velocity can be independently throttled on that partition without throttling other unaffected partitions. This enables organizations to maximize overall migration performance.

Reassembling Partitioned Libraries Post-Migration

As partition transfer jobs reach completion individually, the full SharePoint can be reconstituted in the new environment by:

Rebuilding metadata navigation hierarchies across transferred partitions.
Relinking document versions and dependencies between partitions.
Redirecting or updating search indexes and document URLs cross partitions.

Verifying partition integrity post-migration ensures users can fully leverage the massive SharePoint library as a unified whole after compartmentalized migration batches conclude.

Code Snippets for Advanced Migration Scenarios

Development teams can build custom scripts and applications to assist with advanced SharePoint migration capabilities using snippets like:

PowerShell Scripts to Export SharePoint Content

Export entire SharePoint document libraries or metadata to streamline migrations:

#Install SharePoint Migration Tool Powershell Module 
Install-Module -Name SPMT -Force  

#Establish SharePoint Online Connection
Connect-SPOService -Url https://tenant.sharepoint.com -Credential [email protected]

#Export List Items and Metadata to File  
Get-SPOTenantSite | Export-SPOTenantSite -Path C:\SharePoint\Migration\export.xml

Importing SharePoint Libraries via Migration API

Leverage SharePoint Migration API to import batch content and metadata:

// Construct migration import request
var importRequest = {
  SiteUrl: "https://tenant.sharepoint.com/sites/destination",
  ListName: "Documents", 
  BatchName: "Batch001",
  FilePaths: [
    "C:\Migration\Batch001\documents"
  ]
}

// Import batch via Migration API POST  
fetch('https://tenant.sharepoint.com/_vti_bin/spmt/import', {
  method: 'POST',
  body: JSON.stringify(importRequest)
})

Calling Custom Migration Webhooks

Invoke webhooks to trigger custom migration logic:

//webhook to extend migration tool
const migrationWebhook = {
  id: 'custom-migration-steps',
  
  endpoints: {
    migrationStart: 'https://apps.mycompany.com/migrations/start', 
    migrationComplete: 'https://apps.mycompany.com/migrations/complete'
  }
}

//Register webhook  
fetch('/api/webhooks', {
  method: 'POST',
  body: JSON.stringify(migrationWebhook)
});

With robust APIs and integration capabilities, development teams can enhance third-party migration tools with advanced automation and customization scripts streamlining large-scale SharePoint upgrades, consolidations, and modernization initiatives.

Verifying Completeness and Cleaning Up After Migration

Post-migration, confirm all SharePoint data, users, and permissions moved correctly prior to decommissioning old environments. Useful techniques include:

Running Comparative Content Audits

Scan SharePoint content databases before after migration to validate accuracy:

Compare total sites, libraries, lists, and list items counts.
Sample check document versions, modifications dates, and version histories.
Spot check key metadata fields preserved properly per business expectations.

Identifying any migration script bugs early enables administrators to promptly correct issues before decommissioning legacy farms.

Checking Permissions and Access Levels

Confirm user credentials and permission levels carried over appropriately:

Sample permission levels on sites, libraries, folders and documents.
Verify AD security groups have correct access to resource.
Check unique permissions assigned directly to individual users moved as expected.

Validating user access safeguards against business disruptions as personnel attempt to reuse migrated SharePoint resources.

Redirecting Legacy URLs to New SharePoint

Update links and redirects to ensure continuity post migration:

Redirect old SharePoint URLs to equivalent new site pages.
Fix hyperlinks and content embedded URLs referencing legacy environment.
Update indexes for search engines and internal links to reference new locations.

Smoothly directing traffic to the new SharePoint environment reduces business confusion during and after migration windows.

With content, permissions, and links validated as functional post-move, legacy SharePoint environments can be safely decommissioned.