Backing Up Large Microsoft 365 Tenants with Synology

Performance Deep Dive: Backing Up Large M365 Tenants with Synology NAS

Large Microsoft 365 environments are very different from small business backup deployments. Schools, universities, healthcare groups, law firms, and enterprises may need to protect thousands of mailboxes, large SharePoint libraries, OneDrive accounts, Teams data, and long-term archives. Once backup volumes reach multiple terabytes, performance planning becomes just as important as backup coverage.

For organizations using Synology NAS, Active Backup for Microsoft 365 can provide a powerful and cost-effective way to protect large tenants. However, successful deployment requires proper hardware sizing, storage planning, network design, and backup optimization.

Why Large Microsoft 365 Tenants Need Careful Planning

Large tenants often contain data spread across:

• Exchange Online mailboxes

• OneDrive accounts

• SharePoint sites

• Microsoft Teams content

• Shared mailboxes

• Alumni or former employee accounts

The first backup can be demanding because the system must capture existing historical data. For schools and enterprises, this may include years of emails, documents, collaboration files, and archived records.

Without planning, organizations may experience long initial sync times, storage pressure, slower restores, or backup scheduling conflicts.

Understanding Initial Sync Performance

The initial backup is usually the longest and most resource-intensive stage.

Performance depends on several factors, including:

• Total data volume

• Number of users

• Microsoft 365 throttling behaviour

• Internet bandwidth

• NAS hardware resources

• Disk configuration

• Number of backup tasks

A tenant with several terabytes of data may require days or longer to complete the first full sync. This is normal for large environments. The key is ensuring the NAS remains stable, properly monitored, and configured to continue without interruption.

Incremental Backups Are Much Faster

After the first backup completes, ongoing incremental backups are usually much more efficient.

Instead of copying everything again, the system focuses on changed data such as:

• New emails

• Modified files

• Updated SharePoint content

• New OneDrive documents

• Teams-related changes

For most organizations, incremental performance becomes much more predictable after the initial sync. This is why the first backup should be treated as a deployment phase rather than a normal daily backup job.

Hardware Recommendations for Large Tenants

The right Synology NAS model depends on tenant size, recovery expectations, and future growth.

For larger Microsoft 365 backup environments, businesses should consider:

• Business-class or rackmount Synology systems

• Sufficient CPU and memory resources

• RAID configurations designed for resilience

• Enterprise-grade hard drives or SSDs

• Expansion capacity for future growth

• 10GbE networking where appropriate

Organizations backing up tens of terabytes should avoid underpowered desktop-class systems. A larger tenant needs hardware designed for sustained backup activity, indexing, search, and restore operations. Maximize performance with a Synology Performance Review.

Storage Planning and RAID Design

Storage planning should account for more than the current tenant size.

Businesses should plan for:

• Current Microsoft 365 data

• Annual growth rate

• Retention requirements

• Deleted user retention

• Backup version growth

• Future user expansion

RAID design should balance capacity, redundancy, and performance. For large deployments, usable capacity and rebuild safety are both important. Storage pools should be monitored closely so the environment does not approach capacity limits unexpectedly.

Network and Bandwidth Considerations

Internet bandwidth plays a major role during the first sync.

A slow connection can significantly extend backup windows, especially for large SharePoint and OneDrive environments.

Organizations should:

• Schedule initial backups during lower-traffic periods

• Avoid competing large data transfers

• Use reliable wired connectivity

• Monitor bandwidth usage

• Consider 10GbE internally for faster local restore performance

Even though cloud download speed matters, local network performance also affects restore speed and user experience.

Optimization Tips for Better Performance

Large Microsoft 365 backup jobs should be optimized carefully.

Best practices include:

• Splitting backup tasks by workload or user group

• Avoiding excessive simultaneous jobs

• Monitoring Microsoft 365 throttling behaviour

• Keeping DSM and backup packages updated

• Using business-grade disks

• Setting realistic retention policies

• Testing restores regularly

A clean deployment structure makes troubleshooting easier and improves long-term manageability.

Lessons from Schools and Enterprises

Educational institutions often provide excellent examples because they manage large numbers of accounts with long retention requirements.

Schools may need to protect:

• Current students

• Teachers

• Staff

• Alumni

• Shared departmental data

Enterprises face similar challenges with former employees, project archives, and compliance records.

The biggest lesson is simple: backup design should match the organization’s data lifecycle. Large tenants need scalable storage, predictable retention, and clear recovery procedures.

Why Synology Works Well for Large M365 Backups

Synology Active Backup for Microsoft 365 gives organizations centralized protection for Exchange Online, OneDrive, SharePoint, and Teams. It also helps reduce reliance on per-user backup licensing by allowing businesses to scale storage capacity according to actual data needs. Optimize large M365 backups with proven Synology solutions.

For large tenants, Synology provides valuable advantages:

• Centralized backup management

• Granular restore options

• Long-term retention flexibility

• Local recovery performance

• Scalable storage expansion

• Independent backup ownership

This makes Synology especially useful for schools, nonprofits, and businesses looking for predictable long-term backup costs.

About Epis Technology

Epis Technology helps organizations design, deploy, and optimize Synology backup environments for large Microsoft 365 tenants. The company provides Synology consulting, Microsoft 365 backup planning, storage sizing, performance optimization, disaster recovery planning, and business continuity support. Get expert help with Synology M365 backup consulting.

By combining practical deployment experience with scalable Synology architecture, Epis Technology helps schools and enterprises protect large Microsoft 365 environments while improving recovery speed, cost control, and long-term data resilience.