Amazon Web Services (AWS) offers a suite of cloud storage services. Among the most widely adopted are Amazon S3 and Amazon EBS, known for their robust scalability, performance, and flexibility for a wide range of workloads.
However, AWS also offers Amazon Elastic File System (EFS). This is a serverless file storage service for workloads that need shared, scalable storage for use with AWS services and on-premises resources.
Unlike S3 and EBS, EFS enables multiple instances to access files simultaneously, making it ideal for big data, DevOps, and machine learning applications. Understanding EFS pricing is essential because the service bills across multiple dimensions — storage, throughput, data access, and transfer — and each one can quietly inflate your monthly spend.
But how much does it cost?
This guide breaks down AWS EFS pricing, covering key cost factors and ways to optimize spending.
But first…
How AWS EFS Works
Amazon EFS is a regional service, meaning it spans multiple AZs within an AWS region. Each AZ acts as an independent, isolated infrastructure zone, reducing the risk of failure.
EFS automatically replicates data across these AZs to ensure high availability and fault tolerance.
How Amazon EFS works with Amazon EC2
Amazon EFS enables multiple EC2 instances to share the same file system simultaneously. Unlike Amazon EBS, which attaches to a single EC2 instance at a time, EFS supports concurrent access across instances.
AWS uses mount targets to enable this connection, which serve as access points between EC2 instances and EFS. Each mount target resides within a Virtual Private Cloud (VPC) subnet and allows instances in the same network to access the file system using the Network File System (NFS) version 4 protocol.
This setup ensures that EFS behaves like a traditional shared network drive, enabling multiple instances to read and write files without additional configuration.
How Amazon EFS Works with AWS Direct Connect and AWS Managed VPN
Amazon EFS can be accessed from on-premises servers using AWS Direct Connect or AWS Managed VPN.
AWS Direct Connect provides a dedicated, high-speed link between an on-premises data center and AWS. It bypasses the public internet, reducing latency, congestion, and security risks.
Once configured, on-premises servers can mount EFS as a network drive, ensuring fast, consistent access to files stored in AWS. Direct Connect is best for workloads that require low latency and high throughput.
AWS Managed VPN is an alternative to Direct Connect. It establishes a secure, encrypted tunnel over the public internet, allowing on-premises servers to access EFS without a dedicated connection.
This option is cost-effective and quick to deploy. However, performance depends on internet bandwidth, making it less suitable for high-speed workloads.
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How Amazon EFS Differs From S3 And EBS
Here are the key differences between EFS, S3, and EBS.
|
Feature |
Amazon EFS |
Amazon S3 |
Amazon EBS |
|
Storage type |
File storage |
Object storage |
Block storage |
|
Access |
Multiple EC2 instances can be accessed concurrently |
Accessed via internet APIs; not limited to EC2 |
Attached to a single EC2 instance at a time |
|
Use cases |
Big data analytics, media processing, content management, web serving |
Backup and restore, archival, big data analytics, data lakes |
Databases, enterprise applications, throughput-intensive workloads |
|
Scalability |
Automatically scales as files are added or removed |
Virtually unlimited storage; scales automatically |
Must be provisioned; can be resized manually |
|
Performance |
Offers scalable performance with low latencies |
High durability and availability; performance varies by storage class |
High-performance storage for mission-critical applications |
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In terms of cost, AWS EFS pricing is higher than both S3 and EBS. Let’s break down its pricing and the factors that influence your bill.
AWS EFS Storage Classes And Pricing
Amazon EFS offers three primary storage classes customized to different data access patterns and redundancy requirements:
- EFS Standard: For frequently accessed data, offering high performance with multi-AZ redundancy.
- EFS Infrequent Access (IA): Optimized for data that is accessed less frequently, providing cost savings while maintaining high durability and multi-AZ redundancy.
- EFS Archive: Cost-optimized for long-lived data accessed a few times a year or less, suitable for archival storage needs.
Here is a quick table summarizing the pricing for each storage class in the US East (N. Virginia) region.
|
Storage class | Storage cost (per GB/month) | Read Access Cost (per GB) | Write Access Cost (per GB) |
|
EFS Standard |
$0.30 | $0.03 (Elastic Throughput) | $0.06 (Elastic Throughput) |
|
EFS IA |
$0.016 | $0.01 + throughput charges | $0.01 + throughput charges |
|
EFS Archive | $0.008 | $0.03 + throughput charges | $0.06 + throughput charges |
Note: With Elastic Throughput (the default mode), all storage classes incur read and write charges based on data transferred. IA and Archive tiers also charge a separate per-GB access fee on top of throughput charges.
AWS EFS pricing depends on where and how data is stored. AWS provides two deployment options:
- Multi-AZ (Regional) Storage: This type stores data across multiple Availability Zones (AZs) for high durability and automatic failover. While this ensures reliability, it comes at a higher cost.
- Single-AZ (One Zone) Storage: Stores data within a single AZ, reducing costs by up to 47% compared to Multi-AZ storage. However, it does not offer the same level of redundancy.
AWS further categorizes Single-AZ storage into two classes, both of which offer meaningful savings over their Regional equivalents:
- EFS One Zone Standard ($0.16/GB-month): Suitable for workloads that do not require multi-AZ resilience, offering a lower-cost alternative for frequently accessed data. That is roughly half the cost of Regional Standard at $0.30/GB-month.
- EFS One Zone-Infrequent Access (IA) (~$0.0133/GB-month): Ideal for rarely accessed data, combining One Zone’s cost savings with IA’s lower storage costs.
Other factors that influence AWS EFS pricing include:
1. Throughput Modes
EFS offers three throughput modes, each with different pricing implications:
- Elastic Throughput (default, recommended): Performance automatically scales with your workload. You pay per GB of data transferred — $0.03/GB for reads and $0.06/GB for writes. This is the best fit for most workloads, especially those with variable or unpredictable I/O patterns.
- Provisioned Throughput: Lets you specify a fixed throughput level independent of storage size. This costs approximately $6.00/MiB/s/month for throughput provisioned above your included baseline. Consider this mode only if your workload sustains consistently high throughput and the math works out cheaper than Elastic.
- Bursting Throughput: Scales throughput with file system size and includes burst credits. I/O is bundled into your storage cost, making the bill predictable. However, small file systems may exhaust burst credits during sustained workloads.
A practical decision rule: start with Elastic Throughput and monitor your CloudWatch MeteredIOBytes metrics for two to four weeks. If average throughput consistently exceeds 5% of your peak, run the numbers on Provisioned to see whether it saves money.
2. Backup and replication
Implementing backup and replication strategies enhances data protection but also affects costs:
- AWS backup: Automates backup processes for EFS, with charges based on the amount of data backed up and restored.
- EFS replication: This option enables the replication of your file system across regions or Availability Zones, incurring extra storage and data transfer costs.
3. Data transfer between AWS services
Accessing EFS from other AWS services can lead to data transfer charges:
- Cross-AZ or cross-region access: Accessing your EFS file system across different Availability Zones or regions incurs data transfer fees (approximately $0.01/GB for cross-AZ transfers in most regions).
- Integration with services: Services such as Lambda or EC2 accessing EFS may contribute to higher data transfer costs, depending on the architecture.
4. API requests and Lambda invocations
Using AWS services in conjunction with EFS can influence costs:
- Amazon API Gateway requests: The number of requests to API Gateway can affect overall costs.
- AWS Lambda invocations: Frequent invocations of Lambda functions interacting with EFS contribute to cumulative costs.
5. Region-Specific Pricing
AWS EFS pricing varies by AWS region. Storage and data transfer rates differ across regions, which impacts the total costs depending on where your data is stored and accessed.
Common EFS Billing Surprises
A few billing details catch teams off guard. EFS Archive storage carries a 90-day minimum storage duration — even if you delete a file after a week, you pay for the full 90 days. IA and Archive tiers also impose a 128 KiB minimum billable file size, so a 1 KiB config file moved to IA still gets billed at 128 KiB. And because Elastic Throughput charges per GB of data transferred, workloads with heavy metadata operations (directory listings, stat calls) can accumulate read charges faster than expected.
What a Real EFS Bill Looks Like
Consider a team storing 500 GB in a Regional file system with lifecycle management enabled. Assume 100 GB stays in Standard (actively accessed), 300 GB ages into IA, and 100 GB drops into Archive. With moderate read activity of around 50 GB/month in reads:
- Standard storage: 100 GB x $0.30 = $30.00
- IA storage: 300 GB x $0.016 = $4.80
- Archive storage: 100 GB x $0.008 = $0.80
- Elastic Throughput reads: 50 GB x $0.03 = $1.50
- IA access charges: ~10 GB x $0.01 = $0.10
Estimated monthly total: ~$37.20 — compared to $150/month if all 500 GB sat in Standard with no lifecycle policy. That is a 75% reduction from a single configuration change.
EFS Features You Can Leverage To Optimize Storage Costs
AWS EFS offers several features to help lower costs while keeping storage efficient. Here’s how you can make the most of them:
1. Use lifecycle management
AWS EFS can automatically move files between storage classes based on how often they are used.
- Inactive files are moved to lower-cost storage. If a file has not been accessed for a set time, EFS can move it from Standard to Infrequent Access (IA) or Archive storage. You can configure transition periods of 14, 30, 60, or 90 days.
- Transition-back policies return files on access. You can enable a policy that moves files back to Standard on first access, so performance-sensitive reads are not penalized by IA latency.
- Custom policies help control storage costs. You can set rules that match your needs, automatically ensuring that old data moves to cheaper storage.
This is the single highest-impact optimization for most teams. As the cost scenario above illustrates, lifecycle management alone can reduce storage costs by 75% or more when most of your data is infrequently accessed.
2. Monitor data usage
Checking how often files are used can help you store them in the right class.
- Move rarely accessed files to cheaper storage. Files only needed occasionally should not stay in Standard storage, which costs more.
- Keep frequently used data in high-performance storage. Files that need fast access should remain in Standard or One Zone storage.
3. Choose the Right Throughput Mode
EFS offers three options for managing data transfer speeds:
- Elastic Throughput (default): Scales automatically and charges per GB transferred. Best for most workloads.
- Bursting Throughput: I/O is included in storage cost, but throughput is tied to file system size.
- Provisioned Throughput: Lets you set a custom speed, which is useful for high-performance applications but adds ~$6/MiB/s/month.
Choosing the right mode for your workload prevents overpaying for unnecessary speed.
4. Delete unused files
Removing old or unnecessary files frees up storage and lowers costs.
- Set data retention policies to remove outdated files after a certain period.
- Use automated cleanup scripts to delete unused data regularly.
5. Consider AWS cost optimization services
AWS Cost Explorer helps track EFS spending with detailed reports, while AWS Budgets lets you set cost limits and receive alerts when usage exceeds thresholds. Using these tools, you can monitor trends, control costs, and adjust storage strategies before costs get out of hand.
But with CloudZero, you get more. Think of real-time cost insights, anomaly detection, and precise cost attribution across teams, products, microservices, and more.
Cloudzero:
- Tracks EFS and cloud costs by product, team, or feature
- Monitors AWS, Azure, GCP, Kubernetes, and SaaS spending in one place
- Identifies sudden cost spikes and alerts teams instantly
- Predicts future costs and helps set spending limits
- Breaks down container and pod-level costs
- Offers clear, actionable cost summaries
- Ensures spending aligns with budgets and policies
- Shares cost insights across teams for better decision-making
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Frequently Asked Questions about AWS EFS Pricing
