Amazon EBS Fast Snapshot Restore (FSR)
Fast Snapshot Restore (FSR) allows you to create low-latency and instant-ready Amazon EBS volumes from snapshots, avoiding the usual initialization delay. Normally, when you restore an EBS volume from a snapshot, it experiences lazy loading, which can cause high latency for the first read operations. FSR eliminates this issue.
Key Benefits of Fast Snapshot Restore
- Instant Read/Write Performance: No performance penalty after volume creation.
- Improved Recovery Time: Faster launch times for applications.
- Availability Across Regions & AZs: Enabled per Availability Zone (AZ).
- Cost Optimization: You pay per enabled snapshot and per AZ.
How to Enable Fast Snapshot Restore
Using AWS Console
- Navigate to EC2 → Snapshots.
- Select the snapshot you want to enable FSR on.
- Click Actions → Manage Fast Snapshot Restore.
- Choose the Availability Zones (AZs) where you want to enable FSR.
- Click Enable.
Cost of FSR
FSR is billed per snapshot per AZ, with pricing varying by region. Check AWS Pricing for the latest rates.
Amazon EBS Multi-Attach
Amazon EBS Multi-Attach is a feature of Amazon Elastic Block Store (EBS) that allows a single EBS volume to be attached to multiple EC2 instances at the same time. This can be particularly useful for use cases that require high availability, distributed systems, and applications that need shared block storage.
Here are key points about EBS Multi-Attach:
1. Use Case:
- High Availability: It provides a way to increase fault tolerance by allowing multiple EC2 instances to access the same EBS volume. For example, a cluster of instances running a distributed database could all access the same volume for better data replication and availability.
- Shared Storage: Applications that require shared block storage between multiple EC2 instances can benefit from this feature.
2. Supported Instance Types:
- EBS Multi-Attach is supported only on certain EC2 instance types, including instances with Nitro-based hardware (like C5, M5, R5) and a few others.
3. Volume Type:
- This feature is available for Provisioned IOPS SSD (io1) and Provisioned IOPS SSD (io2) volumes.
- EBS volumes attached to multiple instances must be in the same Availability Zone.
4. Data Consistency:
- When using EBS Multi-Attach, it’s important to understand that data consistency is your responsibility. For example, applications must handle concurrent writes, as EBS volumes do not automatically provide data consistency across multiple writers.
- Typically, applications using this feature need to be able to synchronize writes from different instances or use distributed file systems like Amazon FSx or GlusterFS.
5. Limitations:
- File Systems: Most file systems, such as ext4 or NTFS, are not designed for simultaneous access by multiple EC2 instances, so using shared file systems like Amazon EFS or distributed file systems is recommended for high concurrency.
- Performance Impact: Performance might be affected if not carefully configured. Consider the number of instances that are attached and how they will interact with the volume.
6. How to Use Multi-Attach:
- Attaching to Multiple Instances: You can attach an EBS volume to multiple instances via the AWS Management Console, CLI, or SDK. When you create the volume, simply select the “Multi-Attach” option.
- Managing Volumes: You can detach the volume from one instance and attach it to another, as long as it’s within the same Availability Zone.
Summary of Key Limits for Amazon EBS Multi-Attach:
| Limit | Details |
|---|---|
| Max Instances per Volume | Up to 16 EC2 instances per volume (same AZ) |
| Supported Volume Types | Only io1 and io2 EBS volumes are supported for Multi-Attach |
| Attachment Scope | Can attach to instances in the same Availability Zone (AZ) and same VPC |
| Volume Performance | Performance (IOPS/Throughput) is shared across all instances attached to the volume |
| Consistency | Data consistency must be managed at the application level (e.g., clustered applications) |
| Snapshot Behavior | Snapshots are supported but consistency across instances is not guaranteed without application coordination |
| Detach and Re-attach | Volume can only be detached from all instances at once |
| Pricing | Charged based on provisioned storage and IOPS, regardless of number of attachments |