Choosing between block, file and object storage
The same physical media can support very different ways of accessing data. The correct model depends on what the application expects to see, who owns the file system and how data must be shared, protected and scaled.
The difference is what the consumer sees and controls
Block, file and object storage can use the same network and even the same underlying capacity. They expose fundamentally different interfaces to the consumer.
The host receives a logical device
The storage system exposes blocks. The consuming host normally creates and manages the file system, volume manager or database layout on top.
- Typical access: iSCSI, Fibre Channel and NVMe-oF
- Strong fit: VM datastores, databases and boot volumes
- Requires disciplined path ownership and multipathing
The client receives paths, files and directories
The storage server owns the file system and provides naming, permissions, locking and shared access semantics to clients.
- Typical access: SMB and NFS
- Strong fit: collaboration, home directories and shared content
- Client behaviour depends on permissions, locking and protocol features
The application addresses an object by key
Data and metadata are stored as objects inside buckets. Applications use an API rather than mounting a conventional disk or shared file system.
- Typical access: S3-compatible API, CLI, SDK or File Manager
- Strong fit: backup, archives, application data and large datasets
- Not a drop-in POSIX file system and usually rewrites whole objects
Where the file system sits changes the operational model
Do not treat these as performance tiers. A file service can be faster than a poorly designed block path, and an object service can be the correct high-scale answer even when it is not suitable for a mounted database volume.
Compare the interface before comparing products
| Model | Consumer addresses | Namespace | File-system ownership | Typical access | Good starting point for | Watch carefully |
|---|---|---|---|---|---|---|
| Block | Logical blocks on a disk or namespace | Created by the host | Host, hypervisor or clustered application | iSCSI, FCP, NVMe/TCP, NVMe/RDMA, NVMe/FC | VM datastores, databases, boot and application volumes | Multipathing, fencing, concurrent writers, host compatibility and failover behaviour |
| File | Path, directory and filename | Presented by the storage server | Storage server | SMB and NFS | Shared team data, profiles, media, repositories and general NAS workloads | Identity mapping, permissions, locking, metadata load and protocol-specific features |
| Object | Bucket, object key and API operation | Flat or prefix-based object namespace | No conventional client file system | S3-compatible REST API, CLI and SDKs | Backup, archives, cloud-native applications and large unstructured datasets | Application compatibility, object rewrite behaviour, consistency expectations, retention and access policies |
The table describes access semantics. Performance, availability and data protection depend on the complete implementation and architecture.
Begin with what the workload must consume
Does it expect a disk, LUN or NVMe namespace?
The host needs to create the file system or manage the volume directly.
Do users or applications need directories and file locking?
Clients should browse and share named files without owning the underlying file system.
Does the application use buckets, keys, metadata or S3 calls?
The workload is designed around API access, scale-out capacity or object retention.
Common starting points—not universal rules
VMware and Hyper-V datastores
Use supported block protocols when the hypervisor expects a shared device. NFS and SMB may also be valid where the hypervisor and design support them.
Databases
Block storage gives the host or database direct control of the volume layout. File storage remains valid for supported database and backup workflows.
User and departmental data
SMB or NFS provides shared paths, permissions and locking without requiring each client to manage a disk.
Media and shared content
File protocols suit applications that expect directories, filenames, random updates and concurrent collaboration.
Backup and immutable retention
S3 is a strong target when backup software supports object repositories, versioning or retention workflows.
Applications, archives and AI datasets
Object APIs suit large datasets, metadata-driven access and applications designed to work with buckets and keys.
One platform can provide several services without making them identical
A storage platform may expose block, file and object access from common infrastructure. Each service still needs its own compatibility, availability, security and data-protection design.
Avoid uncontrolled cross-protocol access. Presenting the same data through unrelated interfaces can create locking, ownership or consistency problems unless the platform explicitly coordinates those semantics.
Different platforms cover different operational models
The products below are examples of how the three access models can be implemented. Product selection should follow the required service, availability model and scale—not the other way around.
| Platform | File services | Block services | Object services | Architectural role |
|---|---|---|---|---|
| euroNAS Premium | SMB and NFS from a standalone storage server | FC, iSCSI/iSER and NVMe-oF targets on qualified hardware | S3 with an integrated S3 File Manager for straightforward object-service requirements | Single-server storage OS, including deployment as a Virtual Storage Appliance |
| euroNAS HA Cluster | Highly available SMB and NFS services | Highly available FC, iSCSI/iSER and NVMe-oF targets on qualified hardware | S3 with an integrated S3 File Manager alongside the storage services | Two-node automatic service failover using synchronous Mirror or a shared-storage model; asynchronous ZFS replication is a separate DR option |
| eEKAS | Scale-out SMB and NFS | iSCSI/iSER and NVMe-oF targets; no FC target | Scale-out S3 with quotas, billing integration and S3 File Manager | Ceph-based scale-out storage without a fixed two-node boundary |
| eEVOS | Consumes compatible external file services where required | Consumes compatible external shared block storage through integrated initiators | Applications can consume object services; eEVOS is not presented as an object target here | Virtualisation platform with integrated Backup & Disaster Recovery; not a general-purpose storage target in this comparison |
euroNAS Premium
File, block and S3 services—including the integrated S3 File Manager—from one storage server or virtual appliance.
Premium details →HA Cluster
File, block and S3 services with automatic service failover, including the integrated S3 File Manager.
HA Cluster details →eEKAS
Distributed Ceph platform for block, file and object services.
eEKAS details →eEVOS
Compute platform that consumes and integrates storage according to the selected architecture.
eEVOS details →Move from the access model to the protocol and architecture
Block protocol comparison
Compare Fibre Channel, iSCSI, iSER, NVMe/TCP, NVMe/RDMA and NVMe/FC.
Choose a block protocol →S3 for enterprise IT
Explore object access, AWS CLI compatibility, retention and the integrated S3 File Manager.
Explore S3 object storage →Shared storage for virtualisation
Relate the access model to VMware, Hyper-V and Virtual Storage Appliance designs.
Explore virtualisation storage →Standards and vendor-neutral technical guidance
Definition of blocks and the host-owned file-system model.
Open SNIA definition →Microsoft’s overview of SMB network file sharing and protocol capabilities.
Open Microsoft guidance →The standards-track specification for NFS version 4.1.
Open RFC 8881 →Objects, keys, metadata and buckets in the S3 access model.
Open AWS guidance →Choose the access model before choosing the appliance
We can review workload expectations, sharing requirements, protection objectives and the operational boundaries of each service.
This page provides architectural guidance for business and enterprise environments. Compatibility, availability and performance must be validated for the complete host, network and storage design.