EBS vs EFS: A Deeper Look at AWS Cloud Storage Services

AWS gives you a few different ways to store files in the cloud. The three main options are Amazon Elastic File System (EFS), Amazon Elastic Block Store (EBS), and Amazon Simple Storage Service (S3). They each work differently, and picking the right one depends on what you’re trying to do.

EBS vs EFS

EFS and EBS are both AWS storage services, but they’re built for different things.

How they work

EFS is a network file system that lots of EC2 instances can access at the same time. It uses the NFS protocol, so you mount it like any other network drive. If you need shared storage across multiple servers, EFS handles that.

EBS, on the other hand, works more like a local hard drive. You attach it to a single EC2 instance, and that instance sees it as a disk. EBS volumes don’t share well — one volume, one instance.

Performance

EFS scales automatically for throughput, which is nice. You don’t have to provision capacity ahead of time. It’s a good fit when you need consistent file sharing across many machines or when read/write patterns vary a lot.

EBS gives you more predictable latency and throughput for individual workloads. The current volume types are gp3 and io2 (gp2 and io1 still exist but gp3/io2 are what AWS recommends for most cases now). You can also tune IOPS and throughput separately with io2.

When to use each

EFS makes sense for:

• Content management systems with multiple web servers
• Media processing where instances need the same files
• Shared home directories or application configs
• Development environments accessed by multiple machines

EBS is better for:

• Databases (your MySQL, PostgreSQL, etc.)
• Anything that needs very low latency disk access
• Boot volumes for EC2 instances
• Applications that don’t need shared storage

EBS vs. EFS: Side-by-Side

On-Premises Access

EBS

EBS doesn’t work on-premises. It’s an AWS-only service.

EFS

You can access EFS from on-premises through AWS Direct Connect or VPN. This requires some setup, but it’s doable if you need a hybrid cloud setup.

Making the Choice

Here’s a simpler way to think about it:

1. Need shared files across many servers? EFS.
2. Running a database or single-instance app? EBS.
3. Storing objects (images, backups, static files)? S3.

The real question is usually whether you need shared access. If yes, EFS. If no, EBS (or S3 depending on what you’re storing).

Performance characteristics

For EFS, AWS elastic throughput handles variable workloads well. You get burst capacity for spikes.

For EBS, gp3 gives you 3,000 IOPS and 125 MB/s throughput by default, and you can increase either independently. io2 is the higher durability option (99.999% instead of 99.9%) with up to 64,000 IOPS per volume.

Pricing

AWS pricing has changed a bit since many guides were written. Here’s what the current picture looks like:

EFS pricing

• Standard storage: around $0.30 per GB-month
• Infrequent Access (IA): around $0.025 per GB-month
• You can set lifecycle policies to move old data to IA automatically
• Data transfer costs apply on top

EBS pricing (current volume types)

• gp3: around $0.08 per GB-month, with separate IOPS and throughput costs
• io2: around $0.125 per GB-month plus IOPS costs
• st1 (throughput-optimized HDD): around $0.045 per GB-month
• sc1 (cold HDD): around $0.02 per GB-month
• Snapshots to S3 cost about $0.05 per GB-month

EBS gp2 and io1 still exist but AWS has moved new recommendations to gp3 and io2. gp3 in particular gives you more for less money compared to gp2.

One thing to keep in mind: EFS pricing includes the file system storage, but you also pay for data transfer. EBS pricing is more straightforward but remember that snapshots use S3 storage which has its own pricing.

Conclusion

EFS, EBS, and S3 each solve different problems:

• EFS is shared file storage for multiple EC2 instances
• EBS is high-performance block storage for single instances
• S3 is object storage for anything you access as files or need extreme durability

If you’re building something that needs shared files across servers, start with EFS. If you’re running a database or need the fastest possible disk for one server, go with EBS. And if you’re storing backups, images, or static content that doesn’t need to be mounted as a drive, S3 is usually the most cost-effective choice.

Most applications end up using a combination of all three — and that’s fine. They complement each other rather than compete.