Our on-prem storage is at capacity. What is the best cloud storage solution for enterprise file archiving?

When your on-premises storage hits capacity, moving to an enterprise cloud archiving solution depends heavily on your retrieval frequency, compliance/retention requirements , and existing cloud ecosystem . For true long-term archiving (data accessed less than once a year), the "Big Three" hyperscalers offer ultra-low-cost cold tiers.

The best enterprise solutions break down as follows:

• Amazon S3 Glacier (Deep Archive): The industry standard for deep cold storage. It boasts the lowest baseline storage cost (starting around $0.00099 per GB/month), with retrieval times ranging from minutes (Express) to 12–48 hours (Deep Archive). Best if you are already in the AWS ecosystem or need rock-solid object lock compliance features.
• Azure Archive Storage: The ideal choice if your enterprise is a Microsoft/Active Directory shop. Priced similarly to Glacier (around $0.00099 – $0.002 per GB/month) with up to 15-hour retrieval times. It requires data "rehydration" before reading and enforces a strict 180-day minimum retention period.
• Google Cloud Storage (Archive): Generally slightly higher base storage cost (approx. $0.0012 per GB/month), but offers the unique advantage of fast data availability and distinct lifecycle configurations. However, it enforces a 365-day minimum retention period and higher data retrieval fees.
• Specialized Cold Storage (e.g., Wasabi or Backblaze B2): If you want to avoid complex multi-tier lifecycle fees, egress penalties, and confusing API retrieval pricing, enterprise hot-cloud-compatible alternatives offer a flat, low-cost tier without separate retrieval charges.

To design an effective offload strategy, look into automated lifecycle management policies so that files older than a specific threshold (e.g., 90 days) automatically transition from your primary storage to the archive tier.

To help narrow down the exact right choice, tell me:

• How much data do you need to migrate (and your daily/monthly growth rate)?
• What is your primary cloud ecosystem (AWS, Azure, Google Cloud, or multi-cloud)?
• Do you have strict compliance mandates (e.g., SEC, HIPAA, or a required 7-year retention)?

For enterprise file archiving (moving older files off saturated on-prem storage), the “best” solution is usually not a generic cloud drive like consumer file sync—it is a cloud object archive platform with lifecycle policies, immutability, encryption, and hybrid migration tooling. The right choice depends heavily on your existing environment and compliance needs.

Top enterprise archive options

Amazon Web Services, Inc. Google Cloud## My typical recommendation by scenario

1. You are primarily a Microsoft shop

Choose Azure Blob Storage Archive + lifecycle management.

Good fit if you already use:

• Active Directory / Entra ID
• Microsoft 365
• Windows file servers
• Azure Backup or Azure hybrid services

A common architecture:

• Keep active files on-prem or in Azure Files
• Automatically move inactive files to Blob Cool/Archive tiers
• Apply retention and immutability policies

2. You need the lowest-cost long-term archive

Choose AWS S3 Glacier Deep Archive.

Good for:

• Legal records
• Compliance archives
• Old project data
• Backups
• Media repositories

AWS positions Glacier classes specifically for long-term retention with different retrieval speeds and costs.

3. You need archive plus analytics/search later

Consider Google Cloud Storage Archive/Coldline.

Useful when archived data may later feed:

• AI workloads
• Data lakes
• Analytics platforms

Google provides multiple storage classes including Nearline, Coldline, and Archive for different access patterns.

Important: do not just “copy files to the cloud”

For enterprise archiving, I would evaluate these capabilities:

• File migration tooling - Preserves permissions, timestamps, ownership, and metadata
• Immutable retention - WORM controls for regulatory data
• Lifecycle policies - Automatically move files from hot → cool → archive tiers
• Encryption - Customer-managed keys if required
• Ransomware protection - Versioning, object lock, anomaly detection
• Search/indexing - Ability to find archived content without restoring everything
• Exit strategy - Avoid designs that make future migration extremely expensive

Hybrid archive products worth evaluating

Many enterprises do not migrate directly from NAS/file servers into raw object storage. They use an archive layer such as:

• NetApp ONTAP FabricPool / SnapMirror approaches
• Dell Technologies storage tiering solutions
• Veeam Software for backup/archive workflows
• Commvault for enterprise data management

A practical migration pattern

1. Classify data:

• Active (<90 days)
• Infrequent (3–12 months)
• Archive (>1 year)

2. Move cold data first:

• Old departmental shares
• Completed projects
• Historical documents

3. Implement:

• Lifecycle rules
• Retention policies
• Encryption
• Monitoring

4. Keep a small on-prem cache for frequently accessed files if users still need SMB-style access.

Short answer

For most enterprises:

• Microsoft-centric environment → Azure Blob Archive
• Maximum scale and lowest archive cost → AWS S3 Glacier
• Data science / analytics focus → Google Cloud Storage Archive

If you tell me:

1. current storage platform (NetApp, Dell, Pure, Windows file servers, etc.),
2. approximate capacity (10 TB, 500 TB, multiple PB),
3. retention requirements, and
4. whether users still need normal file-share access (SMB),

I can suggest a more specific architecture.

If your goal is to offload large volumes of aging on-prem files while retaining them for years, I’d make Amazon S3 with S3 Glacier storage classes the default choice—unless your organization is heavily standardized on Microsoft/Azure.

My recommendation

1. AWS S3 + S3 Glacier — best overall

aws.amazon.com offers mature lifecycle policies, object locking/immutability, versioning, encryption, extensive compliance controls, and virtually unlimited scalability. For true archive data, S3 Glacier Deep Archive is designed for the lowest-cost long-term retention; Glacier Instant Retrieval is better when archived files occasionally need immediate access.

For your specific problem, S3 File Gateway is particularly attractive: it presents an SMB/NFS interface to your on-prem environment while storing the underlying data as S3 objects. AWS explicitly positions it for archive repositories and says it can free capacity in existing on-prem storage.

2. Azure Blob Storage — best if you're Microsoft-centric

azure.microsoft.com is arguably the better choice if you're already using Microsoft 365, Azure, Entra ID, Windows Server, and Microsoft security/compliance tooling. Its Hot/Cool/Cold/Archive tiers let you move data progressively toward cheaper storage. Archive is intended for rarely accessed compliance and long-term retention data.

Azure also has Azure File Sync, which can maintain a local Windows file-server experience while tiering less-used data to Azure—often a very natural architecture for an existing Windows file-server environment. Microsoft's own comparison describes Azure's hybrid approach alongside AWS S3 File Gateway.

3. Google Cloud Storage — strong alternative

cloud.google.com is compelling if your organization already runs heavily on GCP or has analytics/ML workloads consuming the archive. Its Standard, Nearline, Coldline and Archive classes provide graduated storage economics.

What I'd deploy

For a typical enterprise with an on-prem SMB/NFS file estate:

Users → existing file server/NAS → cloud tiering/gateway → object storage → lifecycle policies → archive tier

I'd avoid simply dumping everything directly into the deepest archive tier. Instead:

• Active files: retain locally / cloud hot tier.
• 90–180+ day inactive files: move to cool/cold storage.
• Long-term inactive files: automatically transition to Glacier Deep Archive or Azure Archive.
• Compliance records: enable immutability/WORM retention where required.
• Deleted files: use versioning/soft-delete and defined retention policies.
• Migration: copy the existing archive first, validate it, then reclaim on-prem capacity.
• Monitoring: track retrieval volume and egress costs—these can matter much more than the raw storage price.

One important caveat: archive storage is not necessarily "cheap file storage." For example, Azure Archive data must be rehydrated before it can be read and can take up to 15 hours; AWS provides multiple Glacier classes specifically to trade retrieval speed against cost.

Bottom line

If you tell me roughly how much data you have (e.g. 100 TB, 500 TB, 5 PB), your current NAS/file platform (NetApp, Dell, Windows Server, etc.), and how often archived files need to be retrieved, I can narrow this down to a specific architecture and estimate the monthly cost.

Azure also has Azure File Sync, which can maintain a local Windows file-server experience while tiering less-used data to Azure—often a very natural architecture for an existing Windows file-server environment. Microsoft's own comparison describes Azure's hybrid approach alongside AWS S3 File Gateway.

3. Google Cloud Storage — strong alternative

cloud.google.com is compelling if your organization already runs heavily on GCP or has analytics/ML workloads consuming the archive. Its Standard, Nearline, Coldline and Archive classes provide graduated storage economics.

What I'd deploy

For a typical enterprise with an on-prem SMB/NFS file estate:

Users → existing file server/NAS → cloud tiering/gateway → object storage → lifecycle policies → archive tier

I'd avoid simply dumping everything directly into the deepest archive tier. Instead:

• Active files: retain locally / cloud hot tier.
• 90–180+ day inactive files: move to cool/cold storage.
• Long-term inactive files: automatically transition to Glacier Deep Archive or Azure Archive.
• Compliance records: enable immutability/WORM retention where required.
• Deleted files: use versioning/soft-delete and defined retention policies.
• Migration: copy the existing archive first, validate it, then reclaim on-prem capacity.
• Monitoring: track retrieval volume and egress costs—these can matter much more than the raw storage price.

One important caveat: archive storage is not necessarily "cheap file storage." For example, Azure Archive data must be rehydrated before it can be read and can take up to 15 hours; AWS provides multiple Glacier classes specifically to trade retrieval speed against cost.

Bottom line

When on-premises storage hits capacity for enterprise file archiving, the "best" solution isn't a consumer file-sync service—it's hyperscale object storage with dedicated archive tiers or a hybrid cloud file tiering gateway.

The ideal choice depends entirely on how often you need to access those archived files and your compliance/retention requirements.

Tier 1: Hyperscale Cloud Object Storage (Lowest Cost per Gigabyte)

If your primary goal is compliance, long-term retention (years/decades), and pennies-per-gigabyte pricing, the top hyperscalers provide the gold standard for backend archive storage via Amazon Simple Storage Service (S3), Microsoft Azure , and Google Cloud Platform.

1. Amazon S3 Glacier (Flexible / Deep Archive)
   • Best for: Massive petabyte-scale data that is rarely or never touched.
   • Cost & Retrieval: S3 Glacier Deep Archive offers the absolute lowest storage cost in the industry (often under $0.001 per GB/month), though retrieval takes anywhere from 12 to 48 hours. Flexible Glacier offers faster retrieval (minutes to hours) for a slightly higher fee.
   • Why it fits: Lifecycle policies can automatically push files from standard S3 hot storage down to Glacier based on age.
2. Microsoft Azure Archive Storage
   • Best for: Enterprises deeply embedded in the Microsoft 365 / Azure ecosystem.
   • Cost & Retrieval: Comparable pricing to AWS Glacier with offline retrieval tiers. Seamless integration with Azure Purview for compliance and data governance.
3. Google Cloud Storage (Archive Tier)
   • Best for: Organizations leveraging GCP for data analytics or machine learning pipelines where archived data might eventually be queried.
   • Cost & Retrieval: Features the lowest minimum storage duration (90 days) among major hyperscalers, making it slightly more flexible if data lifecycles change rapidly.

Tier 2: Dedicated Cloud-Native & Hybrid Archival Solutions (Easiest to Manage)

If you don't want to build custom APIs or lifecycle scripts on top of raw object storage, hybrid file architectures cache active data locally and automatically tier cold files to the cloud.

1. Egnyte
   • Best for: Enterprises needing a hybrid file server replacement.
   • Why it fits: It caches frequently used files locally for LAN-speed performance while intelligently moving stagnant, archived files to cheaper cloud tiers in the background without breaking folder structures or user habits.
2. Backblaze B2 + Cyberduck / Native Integrations
   • Best for: Mid-to-large enterprises looking for predictable, low-cost cloud backup and archive without complex egress fee structures.
   • Why it fits: Known for significantly lower and more transparent pricing models compared to AWS/Azure, making budgeting straightforward.

Summary Recommendation Matrix

• Choose AWS S3 Glacier Deep Archive if you have strict regulatory compliance data that you will almost never read, and you want the lowest possible operational cost.
• Choose a Hybrid Solution like Egnyte if your end-users still need transparent, file-explorer-style access to historical archives without IT intervention.

To help narrow down the right architectural fit, tell me:

• How much data do you need to archive (TB/PB)?
• What is your expected retrieval frequency (daily, monthly, or "just in case" emergency only)?
• Are you bound by specific compliance or retention regulations (e.g., HIPAA, SEC, GDPR)?

For enterprise file archiving (moving older files off saturated on-prem storage while keeping them secure and recoverable), the “best” solution usually depends on your ecosystem, compliance needs, and how quickly you need to retrieve archived files. For most enterprises, the leading choices are:

Amazon Web Services, Inc. TechTarget## My typical enterprise recommendation

For a company with full file servers/NAS and a capacity problem, I would usually avoid simply dumping files into a cloud bucket. A better architecture is:

Existing file shares/NAS → archive/tiering software → cloud object storage

This gives users a normal file experience while automatically moving inactive files to cheaper cloud storage.

Common patterns:

• Active files: remain on-prem or in a hot cloud tier.
• Inactive files: moved to cloud archive tiers.
• Retention/legal holds: enforced with immutability and governance controls.
• Recovery: users or administrators recall archived files when needed.

Best choice by scenario

Choose AWS if:

• You have very large archives (hundreds of TBs to PBs).
• Cost optimization is the primary goal.
• You need many storage classes, from instant archive access to deep archive. AWS S3 Glacier tiers are specifically designed for long-term retention and archive workloads.

Choose Azure if:

• Your environment is mostly Windows, Microsoft 365, Active Directory/Entra ID, and Microsoft security tooling.
• You want cloud governance integrated with your existing Microsoft stack.

Choose Google Cloud if:

• Your workloads already run on Google Cloud.
• You want archive storage integrated with data analytics workflows. Google Cloud offers Archive storage for long-term retention use cases.

Enterprise features I would require

Before selecting a platform, make sure it supports:

• Immutable retention / WORM storage
• Encryption with customer-managed keys (if required)
• Audit logging
• Role-based access controls
• Lifecycle policies
• File metadata preservation
• SMB/NFS migration support
• Bulk migration tools
• Backup integration
• E-discovery and legal hold capabilities

Migration approach

A practical rollout:

1. Inventory your file shares:

• Size by department
• Last access date
• File types
• Retention requirements

2. Separate:

• Active working data
• Dormant data
• Regulatory archive data
• Duplicate/obsolete data

3. Pilot with one department:

• Move older files first
• Validate permissions and retrieval
• Measure user impact

4. Expand gradually:

• Enable lifecycle policies
• Reduce on-prem capacity pressure
• Keep a recovery plan

If you tell me:

• current storage platform (NetApp, Dell EMC, Windows File Server, Synology, etc.),
• approximate size (TB/PB),
• number of users,
• compliance requirements (HIPAA, FINRA, SEC, legal hold, etc.),
• and whether users need normal file-share access,

I can narrow this down to a specific architecture and vendor shortlist.

Here are top web results for exploring this topic:

Cloudian·https://cloudian.com**Best Enterprise Storage Solutions** : Top 5 in 2026 Notable Enterprise Storage Solutions. 1. Cloudian HyperStore. Cloudian-logo. Cloudian HyperStore object storage software is an enterprise-grade, software-defined storage platform for managing massive ShareArchiver·https://sharearchiver.com 7 Best Enterprise Cloud Archiving Solutions in 2026 Best for: Enterprise file and unstructured data archiving. ShareArchiver is designed around a problem many large organizations eventually face: enormous quantities of files accumulate on primary stora PCMag·https://www.pcmag.com The Best Business Cloud Storage and File -Sharing Providers for 2026 The trend has been accelerated by the distributed nature of modern work, with many staffers working from home. It isn't practical to expect a small business's IT staff to maintain an entire workforce' Reddit·https://www.reddit.com What are people using for on-prem storage these days? : r/sysadmin A new on-prem Windows file server is an obvious choice. Or two Windows servers with DFS for availability, because my blood pressure always goes up when I reboot the file server for updates. TrueNAS is Investopedia·https://www.investopedia.com 8 Best Cloud Storage Solutions for Small Business - Investopedia Our top picks include AWS from Amazon, Box, Dropbox, JustCloud, Microsoft OneDrive, OpenDrive, SpiderOak, and Syncplicity. Get personalized, AI-powered answers built on 27+ years of trusted expertise. FileCloud·https://www.filecloud.com The 5 Best Cloud Storage Providers for your Business - FileCloud Dropbox Business. Dropbox is one of the best cloud storage providers. It offers cloud storage, personal cloud, file synchronization, and client software. You can easily access your files by signing in Solix Technologies, Inc.·https://www.solix.com**Best** Hybrid Cloud Storage Options for Cost-Effective Archiving Hybrid cloud is the most cost-effective model for long-term enterprise archiving. The biggest savings come from tiering cold data to low-cost cloud object storage. Cost-effective archiving depends mor Solutions Review·https://solutionsreview.com The 29 Best Enterprise Data Storage Companies for 2026 Users are enabled to select from object, block, and file storage services as well as cloud data migration options when selecting their solution. The vendor's various platforms also support both applic stonefly.com·https://stonefly.com/blog/enterprise-archive-storage-solutions/**Archive Storage** Systems For Cost-Efficient, Long-Term Data Retention Enterprise archive storage solutions with on-prem, cloud, and GPA 4.0 options for secure, compliant, and energy-efficient long-term data retention. Spiceworks Community·https://community.spiceworks.com**Best** cost-effective per terabyte and fully cloud -based backup solutions Backblaze B2 and Wasabi are both solid picks. They're cheap, easy to work with, and don't hit you with egress fees. Google Nearline or Coldline can work too if the data isn't accessed often, but watch

For enterprise file archiving, the "best" solution isn't a single vendor, but a combination of an hyperscaler cold object storage tier paired with an enterprise file gateway or archiving software that abstracts the complexity . Because archives are characterized by write-once-read-rarely data patterns, cost-per-gigabyte and compliance lock-ins drive the decision.

The primary hyperscaler archive tiers and top architectural approaches include:

• Amazon S3 Glacier Deep Archive (AWS): The gold standard for ultra-low-cost, long-term retention. At roughly $0.00099 per GB/month, it is ideal for multi-year compliance data, though retrieval times take up to 12 hours. Pair with AWS Storage Gateway or native lifecycle policies.
• Microsoft Azure Archive Storage: Matches AWS on base cost ($0.00099 per GB/month) and is the natural fit for organizations embedded in the Microsoft 365 / Azure ecosystem. It requires explicit "rehydration" to access files, enforcing a 180-day minimum retention period.
• Google Cloud Storage Archive: Slightly higher storage cost ($0.0012 to $0.0024 per GB/month depending on region), but offers faster data accessibility and unique analytical integrations if your archiving pipeline feeds directly into tools like BigQuery.
• Specialized Enterprise Gateways (e.g., Egnyte, Cohesity, Veritas Enterprise Vault, or Cloudian): If your users still need a familiar file-system view (SMB/NFS) or transparent tiering from on-premises NAS to the cloud without retraining staff on object storage, these hybrid platforms manage the stubbing and policy engine behind the scenes.

To narrow this down, could you share:

• Your approximate total data volume (terabytes or petabytes)
• How often you expect to retrieve or audit the archived files
• Whether your enterprise is already standardized on AWS, Azure, or Google Cloud

For enterprise file archiving from an on-premises environment, my default recommendation would be Azure Files + Azure File Sync if you're primarily a Windows/SMB shop. It is purpose-built for the exact problem you're describing: keep a local file-server namespace and hot data while automatically moving cold files to cloud storage.

Best options

1. Azure File Sync — my first choice for your scenario.
Azure File Sync monitors file access and can retain frequently accessed ("hot") files locally while moving infrequently accessed files to Azure Files. Users still see the familiar file/folder namespace, and opening a tiered file transparently recalls its contents from Azure.

You can configure tiering based on local free-space targets and/or how long files have gone without being accessed. Microsoft recommends starting around a 20% free-space target and tuning based on workload and recall behavior.

2. AWS S3 File Gateway — best alternative.
If you're already heavily invested in AWS, S3 File Gateway is extremely compelling. It exposes an SMB/NFS file interface on-premises while storing the files as objects in S3. It also provides local caching and lets you apply S3 lifecycle policies, versioning, and replication.

This is particularly attractive if "archive" means keep the data cheaply for years and rarely retrieve it, rather than needing the archived files to behave almost exactly like local files.

What I'd deploy

For a typical enterprise Windows environment:

On-prem file servers → Azure File Sync → Azure Files → lifecycle/retention policies

I'd keep perhaps 10–30% of capacity locally as the working set, with older data tiered to Azure. The exact percentage should be based on access patterns rather than simply "old files = archive." Azure specifically recommends monitoring cache-hit rate and recall volume when tuning this.

If you have millions/billions of files, compliance/WORM requirements, very long retention, or extremely low retrieval frequency, I'd evaluate an object-storage archive architecture instead of treating the cloud as an extension of the file server.

If you tell me (1) Windows/Linux, (2) approximate TB, (3) SMB/NFS, (4) retention period, and (5) how often archived files are retrieved, I can narrow this down to a specific architecture and estimate the likely monthly cost.

When your on-premises storage hits capacity, transitioning to enterprise file archiving requires balancing data durability, compliance capabilities (like WORM/immutability) , and long-term cost efficiency . For pure archiving, hyperscale object storage tiers are universally recognized as the gold standard over expensive block or active file shares.

The best enterprise cloud storage solutions for file archiving break down into three primary categories depending on your current ecosystem and priorities:

• Hyperscaler Cold/Archive Tiers (Best for scale, lowest raw gigabyte cost)
• Alternative/S3-Compatible Cloud Providers (Best for predictable billing and avoiding egress shock)
• Dedicated Enterprise Archiving & Hybrid Platforms (Best for governance, eDiscovery, and seamless on-prem extension)

1. The Hyperscaler Cold Storage Tiers (AWS, Azure, GCP)

If you are already embedded in a major public cloud ecosystem, utilizing their dedicated deep-archive object tiers yields the lowest raw storage costs—often fractions of a cent per gigabyte.

• Amazon S3 Glacier (Flexible & Deep Archive): The industry benchmark for massive-scale durability (99.999999999%) and compliance. Glacier Deep Archive offers the lowest price point in the market for data you plan to access once or twice a year, though retrieval can take anywhere from 2 to 12 hours.
• Microsoft Azure Archive Storage: Ideal if your enterprise operates primarily in a Microsoft environment (Active Directory/Entra ID, Microsoft 365). Azure’s archive tier integrates smoothly with enterprise backup and tiering software using native lifecycle management policies.
• Google Cloud Storage (Archive): Offers competitive pricing transparency and rapid millennial-scale data retrieval times compared to traditional cold tiers, making it advantageous if you plan to run analytics on your archive via BigQuery.

2. S3-Compatible Independent Providers (Wasabi, Backblaze B2)

If you want to bypass the complex web of retrieval fees, API operation costs, and data egress charges that hyperscalers tack on, independent cloud providers are ideal.

• Wasabi Hot Cloud Storage: Provides high-performance object storage with zero egress fees and zero API request fees , charging a flat rate per TB. It is 100% S3-compatible, meaning it drops right into existing enterprise backup and archiving tools.
• Backblaze B2: Highly cost-effective object storage with simple pricing models and optional high-throughput performance packages, well-suited for organizations migrating petabytes off local NAS/SAN arrays without hidden billing surprises.

3. Hybrid & Specialized Archiving Gateways (Cloudian, Egnyte, Veritas)

If "archiving" means your users still need transparent, low-latency access to older files without retraining staff or breaking legacy file paths (SMB/NFS), a hybrid gateway or specialized management platform is required.

• Cloudian HyperStore / ObjectScale: Software-defined or appliance-based storage that sits on-prem or hybrid, allowing policy-based tiering straight to public cloud cold storage while presenting a single namespace to your users.
• Egnyte / Box / Tresorit: Best if your archive requires active user collaboration, granular eDiscovery search tools, and strict digital governance rather than just passive byte storage.
• Veritas Enterprise Vault / Archive360: Comprehensive software layer that handles automated policy enforcement, classification, and regulatory compliance (SEC 17a-4, HIPAA, GDPR) before committing the compressed data down to your cloud target of choice.

To help narrow down the ideal path, could you share:

• Roughly how many terabytes/petabytes you need to offload?
• How often you expect to retrieve or search through these archived files?
• Whether you are already committed to AWS, Azure, or a multi-cloud strategy?

If your primary problem is an on-premises file server running out of capacity, my default recommendation would be Azure Files + Azure File Sync with cloud tiering—especially if your environment is Windows/Active Directory-heavy.

Best fit: Azure Files + Azure File Sync

Azure File Sync is specifically designed to extend an on-premises Windows file server into the cloud. It keeps the file/folder namespace on-premises while moving infrequently accessed (“cold”) file content into Azure Files. Users can still open tiered files normally; the data is recalled from Azure when needed.

A typical setup would be:

On-prem file server → Azure File Sync → Azure Files → lifecycle/backup policies

You can configure it to maintain, for example, 20% free space locally, automatically pushing colder files to Azure as the local volume fills. Microsoft recommends starting around 20% free space and tuning based on access patterns and recall activity.

Why I'd choose it:

• Minimal change for existing SMB/Windows file shares
• Users continue seeing familiar folders and drive mappings
• Automatic cloud tiering based on file activity
• Can substantially reduce required local storage
• Supports multiple on-premises servers/sites
• Azure becomes the durable source for the full dataset

One important caveat: don't treat tiering as your backup strategy. Microsoft recommends backing up the Azure file share directly rather than backing up the partially cached on-premises server.

Strong alternative: AWS S3 File Gateway

If your objective is more "move archival data into inexpensive object storage" than "extend my existing Windows file server," I'd look closely at Amazon S3 File Gateway.

It exposes S3 through familiar SMB/NFS interfaces and maintains a local cache, while files are stored as objects in S3. S3 also gives you lifecycle policies, versioning, and replication capabilities.

That makes AWS particularly attractive for large volumes of genuinely cold data that users rarely need to retrieve.

My decision rule

For your stated problem, I'd start with Azure File Sync. It solves the immediate capacity issue without forcing you to redesign how users and applications access the files.

If you tell me roughly how many TB you need to archive, current monthly data growth, how often archived files are retrieved, Windows vs. Linux, and whether you're already an Azure/AWS customer, I can compare the likely 3–5 year cost and architecture of Azure vs. AWS for your environment.