EBS and EFS

Learn all storage tier

and types of disk they use and same for snapshot

1. What is EBS (Elastic Block Store)?

AWS Elastic Block Store (EBS) is a durable, block-level storage service designed for use with Amazon EC2 instances. It provides persistent storage that is similar to a hard drive, allowing data to persist even after an EC2 instance is stopped or terminated. EBS volumes are attached to a single EC2 instance (except for io1/io2 multi-attach) and come in different types optimized for performance (SSD, HDD).

HDD is a traditional storage device that uses spinning disks like DVD disk, offering large capacity at a lower cost but slower performance. SSD uses flash memory with no moving parts, making it much faster, more reliable, but more expensive. Typically, HDDs are used for backups and archival, while SSDs are used for OS, databases, and high-performance workloads

💡 Example Answer: "EBS is a block storage service that provides high-performance, low-latency storage for EC2 instances. It is best suited for applications requiring consistent and high-speed disk performance, such as databases, application servers, and boot volumes."

Volume Type	Backed by	Performance	Best For
gp2/gp3	SSD	Balanced price/performance	Default for general workloads
io1/io2	SSD	High IOPS (up to millions)	Databases, transactional systems
st1	HDD	High throughput	Big data, sequential reads
sc1	HDD	Low cost	Cold data, infrequent access

Feature	SATA / Xen	NVMe / Nitro
Interface	Older (SCSI/SATA)	PCIe (direct to CPU)
Latency	Higher (milliseconds)	Ultra-low (microseconds)
IOPS	Lower	Extremely high
Queue Depth	Single queue	Thousands of parallel queues
Speed	~500 MB/s	3–6 GB/s (or more)

AWS Nitro-based instances (e.g., t3, m5, c5, r5, etc.) use NVMe for EBS and instance store devices to get:

• Faster performance

• Lower latency

• Better scalability

• Consistent naming across platforms (/dev/nvme0n1, /dev/nvme1n1, etc.)

How NVMe Is Mapped in EC2

• Even though EBS is network storage, when attached to a Nitro instance, it’s presented as an NVMe device.

• Example device: /dev/nvme0n1

  • Partition 1 → /dev/nvme0n1p1

• AWS uses a software layer to map the EBS volume to NVMe protocol for higher efficiency.

EBS (Elastic Block Store) gp3, io1, io2, st1, sc1 Network-attached block storage. Independent of the instance. used for Root volume, databases, app data

once ebs modiefied we need to extend the filesystem

by

741 sudo growpart /dev/nvme0n1 1 742 df -h 743 sudo resize2fs /dev/nvme0n1p1 744 df -h

Expands the partition on the disk to occupy the newly available space.

💡 Explanation:

/dev/nvme0n1 → refers to the NVMe disk (your root volume)

1 → means “first partition” on that disk

When you increase an EBS volume’s size from, say, 20 GB → 50 GB in the AWS Console, the disk grows, but the partition inside it doesn’t automatically use that extra space.

2️⃣ sudo resize2fs /dev/nvme0n1p1 ✅ Purpose:

Expands the filesystem (ext4) inside the partition so it can actually use the new space.

💡 Explanation:

/dev/nvme0n1p1 → partition #1 (the one you just grew)

resize2fs → resizes the ext2/3/4 filesystem to match the partition’s new size.

Without this step, the partition might be bigger, but the filesystem inside it would still think it’s small.

2. What is EFS (Elastic File System)?

AWS Elastic File System (EFS) is a scalable, managed, NFS-based file storage service that can be mounted simultaneously on multiple EC2 instances. It is designed to provide high availability and automatic scaling, making it ideal for workloads that require shared access to files across multiple instances, such as web hosting, container storage, and big data applications.

💡 Example Answer: "EFS is a fully managed file storage service that allows multiple EC2 instances to access the same data simultaneously. It automatically scales as data grows and is ideal for shared file storage, web applications, and big data processing."

EBS vs. EFS - AWS Storage Comparison

Feature	EBS (Elastic Block Store)	EFS (Elastic File System)
Definition	Block storage attached to EC2 instances, similar to a virtual disk.	Managed NFS-based file storage that can be mounted across multiple instances.
Purpose	Persistent storage for a single EC2 instance.	Shared storage for multiple EC2 instances.
Access Type	Can be attached to only one EC2 instance at a time (except multi-attach for io1/io2).	Can be accessed simultaneously by multiple EC2 instances.
Use Cases	- High-performance databases (MySQL, PostgreSQL, MongoDB). - Application servers requiring persistent storage. - Boot volumes for EC2 instances.	- Shared storage for multiple EC2 instances. - Web server document root (WordPress, media hosting). - Machine learning & big data workloads.
Performance Modes	General Purpose SSD (gp3, gp2), Provisioned IOPS (io1, io2), Cold HDD (sc1), Throughput HDD (st1).	Bursting mode (default) and Provisioned Throughput mode.
Scalability	Fixed size (1 GiB – 16 TiB per volume); manual resizing required.	Auto-scales from GBs to petabytes.
Max Size per Volume/File System	16 TiB per volume.	Unlimited (up to petabytes).
Resilience	Data replicated within an AZ (availability zone).	Data replicated across multiple AZs in a region.
Multi-AZ Support	No (unless using snapshots for backups).	Yes (built-in multi-AZ replication).
Latency	Low latency, single-instance access.	Higher latency compared to EBS (network file system overhead).
Availability	Tied to a single AZ. Snapshots can be used for backup/restore.	Multi-AZ by default, ensuring higher availability.
Backup & Restore	Uses snapshots to back up data to S3.	Built-in automatic backups via AWS Backup.
Mounting	Needs to be attached to an EC2 instance like a hard drive.	Can be mounted on multiple EC2 instances using NFS.
Throughput	Up to 1,000 MiB/s (depends on volume type).	Up to 10 GiB/s throughput.
IOPS (Operations per second)	gp3: 3,000 - 16,000 IOPS, io2: Up to 256,000 IOPS.	Provisioned up to 1 GiB/s per instance.
Pricing	Pay per GB provisioned + IOPS (if applicable).	Pay per GB stored + read/write throughput.
Best When To Use	- Single EC2 instance needs fast block storage (databases, logs, VMs). - Need high IOPS for transactional workloads.	- Multiple EC2 instances need access to shared storage. - Scalability & elasticity are important.
Limitations	- Cannot be shared between multiple instances (except io1/io2 multi-attach). - Manual resizing needed.	- Higher latency than EBS. - More expensive than EBS for small workloads.

Key Differences Between EBS and EFS:

1. EBS is block storage, while EFS is a shared file system (like an NFS mount).

2. EBS is single-instance, while EFS supports multi-instance access.

3. EBS must be manually resized, but EFS scales automatically.

4. EBS has lower latency and is better for databases, while EFS is better for shared workloads (e.g., web hosting).

🔥 Quick Decision Guide:

• Use EBS for fast, single-instance storage (databases, boot volumes, high IOPS workloads).

• Use EFS for multi-instance shared access (web hosting, file storage, analytics).

Let me know if you need more comparisons! 🚀