4 Self-hosted file sync and share platforms give organizations the familiar experience of consumer cloud drives, with desktop sync clients, mobile apps, web access, sharing links and collaboration, while keeping data on infrastructure they control. Universities, research institutes, public sector bodies, healthcare organizations, telcos and enterprises in regulated industries choose them for data sovereignty, compliance and cost. The storage backend behind these platforms determines how far they can scale, how reliable they are and how much they cost per user. This article explains how self-hosted sync and share platforms use storage, the backend options, the design considerations that matter at scale and how sovereignty and security requirements shape the choice. For related context, see our hub on SaaS file storage. Why organizations self-host file sync and share Data sovereignty: keeping files in-country and under national law, which is a major driver in Europe, particularly for public sector, education and research, and increasingly in Japan, the Middle East and elsewhere. Compliance: meeting sector rules for health, finance, government and research data. Control: deciding where data lives, who can access it and how it is retained. Integration: connecting to internal identity systems, collaboration tools and research infrastructure. Cost at scale: for large user bases with large quotas, owned infrastructure can be cheaper than per-user subscriptions. Service providers: telcos and hosting companies offer white-label sync and share services to business and consumer customers. Popular self-hosted platforms include open-source and commercial options. Many of the widely used platforms support S3-compatible object storage as a backend. How sync and share platforms use storage A typical platform has three storage layers: File content: the actual bytes of every file version. Metadata database: file names, folders, owners, shares, versions, permissions and activity. Caches and indexes: thumbnails, previews, search indexes and session data. The metadata database is usually a relational database and is often the first performance bottleneck. File content is where capacity lives, and its backend is the main storage decision. Backend options for file content Local or block storage Small deployments can store files on local disks of application servers or on block storage. This is simple but does not scale well beyond a single server and complicates high availability. NAS or shared file systems Many deployments use NFS or other shared file systems so multiple application servers can access the same files. This works at moderate scale, but very large numbers of files can strain file system metadata, and scale-up NAS becomes costly and complex to grow. S3-compatible object storage Object storage can be configured as primary storage, where the platform stores file content as objects and keeps the folder structure in its database. This approach: Scales to billions of files and petabytes by adding nodes. Simplifies high availability, since every application server accesses the same object store over HTTP. Protects data with erasure coding and multi-site replication. Reduces cost per terabyte compared with high-end NAS. Supports immutability for ransomware protection. Because objects are often stored with opaque identifiers rather than human-readable paths, the metadata database becomes the source of truth for the file tree, which makes database backup and resilience critical. External storage mounts Many platforms can also mount existing storage, such as departmental file shares or other S3 buckets, as external folders. This is useful for integrating existing data without migrating it. Design considerations at scale Metadata database performance Sync clients poll frequently for changes, so metadata databases see heavy read and write loads. Plan database clustering, caching and maintenance carefully; it often matters more than raw storage throughput. Small files Sync and share workloads include huge numbers of small files: documents, code, configuration files and thumbnails. Object storage must handle high request rates with consistent latency. Versioning and trash Platforms keep previous versions and deleted files for recovery. These consume significant capacity. Set retention policies for versions and trash, and include them in capacity planning. Quotas and growth Users’ storage needs grow steadily. Quotas control growth, but generous quotas for research or media users can drive large increases. Forecast by user group. Encryption Platforms may offer server-side encryption, end-to-end encryption or both. Combine platform encryption with encryption at rest on the storage backend, and plan key management. Ransomware protection A compromised user device can sync encrypted files to the server, overwriting good versions. Versioning helps recovery; storage-level immutability and independent backups protect against attackers who reach the server or storage credentials. High availability Run multiple application servers behind load balancers, a clustered database and a resilient object store spanning failure domains, so the service survives server, node and site failures. Sovereignty considerations by region In the EU, public bodies and universities often adopt self-hosted sync and share specifically to keep data under European law and avoid transfers to non-EU providers. Germany and France have seen strong public sector interest in sovereign collaboration platforms. In Japan and the Middle East, data localization and government security programs favor in-country deployments. For these organizations, the storage backend must also be in-country and operated under their control, with no remote access from abroad without approval. Common deployment scenarios University and research Universities deploy sync and share for staff and students, often with large quotas for researchers and integration with research computing. Data volumes grow quickly with research data, so object storage backends and clear retention policies matter. Public sector Government bodies use self-hosted platforms to share documents internally and with citizens or partners while keeping data under national control. Security accreditation, audit logging and strict access control are central requirements. Healthcare Hospitals and health networks share clinical documents, images and administrative files, subject to health data rules. Encryption, access logging and in-country storage are mandatory, and integration with clinical systems may be required. Service providers Telcos and hosting providers run multi-tenant sync and share services for business and consumer customers, with each customer isolated and billed by usage. Multi-tenant object storage with per-tenant accounts or buckets simplifies isolation and reporting. Migrating to object storage backends Organizations running sync and share on NAS often move to object storage as they grow. Migration typically involves platform-specific tools that copy file content to object storage and update the database, run in batches with verification. Test thoroughly on a copy first, since mistakes can break the link between database entries and file content. Monitoring the service Monitor sync latency, database query times, storage request latency and error rates, capacity per user group and the size of version and trash data. Alerts on sudden spikes in file modifications per user can catch ransomware activity syncing from an infected device before it spreads widely. Sizing a deployment Users and active users, and peak concurrent sync clients. Average storage per user, including versions and trash. File counts, which drive database size and storage request rates. Growth by user group. Protection overhead and multi-site copies. Database and cache resources sized for sync polling and activity. Checklist: self-hosted file sync and share storage Confirm the platform supports S3-compatible primary storage. Size and cluster the metadata database for heavy sync activity. Choose object storage that handles billions of small files. Set retention for versions and trash. Plan quotas and growth by user group. Combine platform encryption with storage encryption and key management. Protect against ransomware with versioning, immutability and backups. Design high availability across servers, database and storage. Keep storage in-country where sovereignty requires. Back up the metadata database as carefully as file content. Putting it together A self-hosted file sync and share platform is only as good as the storage behind it. Object storage as the primary backend lets these platforms scale to large user bases and file counts, simplifies high availability, lowers cost per terabyte and supports immutability, while keeping data on infrastructure the organization controls. Pair it with a well-sized metadata database, sensible retention, strong encryption and in-country deployment, and self-hosted sync and share becomes a credible, sovereign alternative to global cloud drives. Frequently asked questions Can self-hosted sync and share platforms use object storage? Yes. Many platforms support S3-compatible object storage as primary storage for file content. What is the main bottleneck in sync and share platforms? Often the metadata database, which handles frequent sync polling and file operations. Why do organizations self-host file sharing? For data sovereignty, compliance, control, integration and cost at scale. How do you protect sync and share data from ransomware? With versioning, storage-level immutability, independent backups and strong access controls. Do I still need to back up the database if files are on object storage? Yes. The database holds the file tree and links to objects, so losing it can make files hard to recover. Further reading SaaS file storage SaaS regional data residency Telco personal cloud storage Consumer photo and video storage Research data management storage
