Introduction to AWS EBS Snapshots
Here you will find out:
- what Are AWS Snapshots
- how to work with Amazon EBS Snapshots
- how DiskInternals software can help you
Are you ready? Let's read!
Amazon Elastic Block Store (Amazon EBS) is a service that offers Amazon Elastic Compute Cloud (Amazon EC2) instances with permanent block-level storage. Simply put, the service assigns dependable hard disks (also known as volumes) to cloud servers.
Creating snapshots of Amazon EBS volumes is a highly helpful function of Amazon EBS. AWS EBS snapshots, according to Amazon Knowledge Base, are backups of EBS volumes. Are they, however, backups? Let's take a look at how EBS snapshots function and what they're capable of.
What Is EBS Snapshot?
An EBS snapshot is a lazily duplicated point-in-time copy of your Amazon EBS volume to Amazon Simple Storage Service (Amazon S3). EBS snapshots are data copies that are made incrementally. This implies that the next EBS snapshot only contains unique blocks of EBS volume data that have changed since the last EBS snapshot. This is how Amazon AWS EBS Snapshot creates incremental copies of data.
Starting from the time the EBS snapshot was created, each AWS snapshot contains all of the information needed to recover your data. EBS snapshots are linked together in a chain. You will be able to correctly restore your EBS volumes if you use them.
The procedure of deleting an EBS snapshot involves removing just the data associated with that snapshot. As a result, you can securely erase any previous pictures. If you delete an old snapshot, AWS will consolidate the snapshot data, moving all valid data to the next snapshot and discarding any invalid data.
EBS snapshots, according to Amazon, are block-level copies of EBS volumes. As a result, EBS volumes and snapshots have no idea what's on the disk: filesystems, partitions, or software. AWS examines each block, assesses if it contains any data, and if it does, adds it to the snapshot. After the snapshot creation has begun, you can securely write data to your EBS disk, and the EBS snapshot will not be affected. Even though the snapshot is still in the "pending" state, all data written to the disk after the snapshot generation began is included in the EBS snapshot.
EBS snapshot has a number of restrictions as an incremental copy of data. Let's take a closer look at them.
Limitations of Amazon EBS Snapshots
1. Awareness of the application
Various apps and databases publish data to the local storage disk, but they cache their most frequently used data in RAM to provide the greatest potential performance. When data from the RAM cache is written to the local disk, applications and databases "decide" (in case of AWS, this is mostly the EBS volume).
It's possible that data will leave your application/database cache but not be written to the EBS storage. As a result, before producing an EBS snapshot, you should flush your application/database cache. The application/database data is pushed from the RAM cache to the EBS storage.
According to Amazon AWS guidelines, you should follow the basic principles below to perform a proper application-aware snapshot:
Before producing an EBS snapshot, stop the EC2 instance and unmount and disconnect the EBS volume from the EC2 instance.
EBS snapshots do not execute flushing or locking procedures on their own, thus you must do so manually before taking the image. Stopping an instance and unmounting volumes to make a consistent backup of business data is akin to starting a car with a hand crank every time you stop at a red signal.
2. No data copy on-premises
One of the most significant approaches for preventing full data loss and increasing the possibilities of avoiding long-term infrastructure outage is copying backups to a different type of media, such as your local backup storage.
EBS snapshots, on the other hand, are saved on Amazon S3 and cannot be accessed directly. As a result, you won't be able to replicate EBS backups outside of AWS.
3. EBS snapshot deduplication is not integrated.
EBS snapshots can require a significant amount of cloud storage space, for which you will be charged. This problem might be solved through deduplication. AWS, on the other hand, does not have a deduplication option.
4. Retention and Scheduling
One of the most crucial aspects of generating backups is scheduling. To keep your photos up to date, you'll need to set up a snapshotting routine. However, bear in mind that the more snapshots you take, the more storage space you'll need. You'll need a retention strategy if you want to maintain only the set of real photos for a certain amount of time.
You may build up a basic routine by executing Amazon AWS CloudWatch Events rules according to your schedule and selecting the rule that will automate the production of EBS snapshots. You may use a Cron expression in addition to AWS CloudWatch to guarantee that the snapshot is produced at a certain time, making your schedule more sophisticated and customizable.
Cron is a time-based scheduling program. Cron-specific expressions can be used in AWS to conduct actions depending on AWS events.
Amazon CloudWatch, according to the AWS website, is a monitoring solution for cloud resources and AWS-hosted applications. CloudWatch events can be used to trigger actions, such as the production of an EBS snapshot according to a schedule.
The aforementioned snapshot scheduling approach, on the other hand, is a workaround rather than a built-in function found in third-party software that allows you to schedule with a few clicks.
Restoring AWS Instance from EBS Snapshot and AWS Granular Recovery
EBS snapshots, as previously stated, are block-level snapshots that are unconcerned with the sort of data they save. Individual files cannot be accessed directly from an EBS snapshot as a result of this. When you restore data from an EBS snapshot, a new EBS volume is created. Based on when the EBS snapshot was produced, the new EBS volume will be an identical point-in-time replica of the original EBS volume.
EBS snapshots are saved in Amazon S3, according to Amazon literature, however you will not locate your snapshots in any S3 storage available to you. AWS utilizes a similar mechanism to store EBS snapshots, but you don't have access to the S3 storage. As a result, granular recovery cannot be performed straight from EBS snapshots.
You can do anything that Amazon enables you to do with EBS volumes with the new EBS volume recovered from an EBS snapshot.
If you produced an EBS snapshot of the complete EC2 instance, for example, you may attach the new EBS volume to the current EC2 instance and mount the file system. You can quickly sign in when you've recovered. In addition, if you took an EBS snapshot of the root EBS volume, you'll be able to mount your new EBS disk as a root volume on a compatible EC2 instance after recovery and then start the EC2 instance with the new root volume.
Protect your data with VMFS Recovery
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If everything suits you and you decide to export the recovered information, it's time to buy a license and export all found files.
An EBS snapshot, as we discovered, is a form of incremental replica of data. Now you know what data protection constraints AWS snapshots have. Amazon EBS snapshots are difficult to utilize and expensive to secure data with.