I need to delete an automatic DB snapshot.
I have a bunch of snapshots created when I delete stacks by the BackupRetentionPeriod property, and now deleting a stack fails with CREATE_FAILED for AWS::RDS::DBClusterSnapshot - Cannot create more than 100 manual snapshots.
So I need to cleanup some snapshots, but the Delete Snapshot option is greyed out:
Also, why does it say "manual snapshots" in the error when they are automatically created on stack deletion?
My understanding (based on trial-and-error only) is that Automated snapshots, can only be deleted by reducing the retention period. Then wait for the next Automated backup-cycle to run (usually once/day).
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithAutomatedBackups.html#USER_WorkingWithAutomatedBackups.BackupRetention
You may not delete automatic snapshots either from the console or via API/AWS CLI. Furthermore if you have a cluster you may also not reduce the retention period to 0.
The one way to delete automatic backups is to delete the instance/cluster itself:
Automated backups are deleted when the DB instance is deleted. Only manually created DB Snapshots are retained after the DB Instance is deleted.
(from https://aws.amazon.com/rds/faqs/#24)
Related
I have a daily snapshot and understand that the snapshots are incremental, and would only take a snapshot of the difference from the last backup.
So if I take a manual snapshot, would it know to diff from my last automated snapshot? Or does it only know to diff manual snapshots?
The way snapshot works are:
It won't be differentiating between an automated backup or a Manual backup. It checks the existing backup (either a Manual or Automated one) and adds the delta on top of it. .If you have deleted the First backup, then the Second backup becomes the point of reference and it creates a soft link with reference to it.
I'm writing because I'm very confused around mechanism that is responsible for taking EBS snapshots.
First of all as far as I understand the difference between "backup" and "snapshot" - backup is full copy of volume blocks one to one, where snapshot is "delta" approach where only changed blocks are being copied right?
If that definition is right, than I can assume that taking EBS snapshot should be called backup - as we do typically full copy of all blocks that particular EBS is build on.
In almost every documentation from AWS website, I can read that EBS snapshots are taken incrementally (first one is full, then only difference between previous "state"). But after my small exercise on AWS console I was not able to see that in action.
I did snapshot of my EBS volume (50GB) and snapshot had a size exactly 50GB. Than I did another snapshot - again size 50GB. It made me incredible confused :///
All my experience / test were made only using root volume (first attached to EC2 instance). Now I was wondering if I have DB installed (postgreSQL) on EC2 that has only root volume attached, is that safe to make a snapshot of EBS (as a safe backup for my DB) as machine is running? Or unfortunately I should periodically take whole instance offline and only than make a backup of my DB volume?
EBS Snapshots work like this:
On your initial snapshot, it will create a block-level copy of your volume on S3 in the background. On subsequent snapshots it only saves the blocks that have changed since the last snapshot to S3 and for the rest it will keep track of a pointer to the original blocks. The third snapshot will work similar to the second snapshot, it again stores the blocks that have changed since the second snapshot and adds pointers to the other blocks.
If you restore the second snapshot, it will create a new volume and take a look at its metadata store, which pointers belong to that snapshot and then retrieve the blocks from S3 these point to.
If you delete Snapshot two, it will remove the pointers to the blocks that belong to snapshot two. If any of the blocks on S3 has no pointer left, i.e. doesn't belong to a snapshot anymore, it will be deleted.
To you as the client this whole process is transparent - you can delete or restore any snapshot you like and EBS will take care of the specifics in the background.
Should you be more interested in the details under the hood, I can recommend this article: The Jellyfish-inspired database under AWS Block Storage
Suppose if I've a Lambda script to invoke EBS snapshots. Few days later, I'm invoking the snapshot of the same EBS volumes but via AWS CLI with different name and description. Would the new EBS snapshot be incremental by recognizing the EBS volumes or Would it be considered like a new snapshot? Kindly clarify.
Yes, it will be the same incremental snapshot.
However, if you copy the snapshot and encrypt it later on, new one will be created from scratch. From docs:
If you copy a snapshot and encrypt it to a new CMK, a complete (non-incremental) copy is always created, resulting in additional delay and storage costs.
Similarly, if you copy it to a new region:
If you copy a snapshot to a new Region, a complete (non-incremental) copy is always created, resulting in additional delay and storage costs.
More on copying snapshots and incremental support is described in Incremental snapshot copying.
I have created and I have been managing a Postgresql RDS instance using Terraform.
Assuming I perform a terraform destroy, will this also delete the associated RDS snapshots that have been taken via the RDS schedule?
Terraform added the option to keep the automated backups for an RDS with the delete_automated_backups flag. Just set this to false.
When destroying an RDS database you have the option to either create a long lived final snapshot or retain the automated backups which will be deleted as per the schedule they were set for:
Instead of creating a snapshot, you can choose to enable Retain automated backups when you delete a DB instance. These backups are still subject to the retention period of the DB instance and age out the same way systems snapshots do.
Terraform supports keeping a final snapshot by setting the final_snapshot_identifier and making sure that skip_final_snapshot is not set to true.
Unfortunately, Terraform doesn't currently support retaining the automated backups taken from scheduled snapshots but there is an open feature request with a couple of half finished pull requests linked to it.
I am creating new RDS MySQL instances from snapshots and updating their configurations both via the API and through the UI. Regardless of how I create or update instances, these actions automatically trigger new snapshots to be created through some kind of automatic backup process. Is there a way to disable snapshot creation when performing these actions since I do not need the additional snapshots and their creation is causing an unnecessary delay?
I spoke with AWS support and it looks like there is no way to prevent the backup being generated at instance creation time. This is due to how the backup creation on create/update is triggered (it is part of the automated backup process) and limited ability to control this feature (toggle it on and off, but only for existing instances).
Here are some more details in case anyone else runs into the same problems that I did.
I am interested in two scenarios:
Do not create a backup on a RestoreDBInstanceFromDBSnapshot request
Do not create a backup on a ModifyDBInstance request
The backups are controlled by this flag:
BackupRetentionPeriod = 0
Unfortunately this flag is part of an instance and of a snapshot, but can only be set on an instance. Therefore, in order to create an instance with this flag set (and thus no backup generated), the snapshot would have to have this flag disabled. This can only happen if the source instance had this flag disabled. At this point we could consider toggling the flag on the original instance when taking a snapshot, however disabling and re-enabling this flag has negative side effects, including:
There is a way to disable automatic backups for existing instances
however we highly discourage against this because it disables point-in-time
recovery. Once disabled, re-enabling them will only restore the backups
starting from the time you re-enable automatic backups.
We would lose all existing backups on the original instance. The end result is that there is not an effective way to avoid creating the first backup when an instance is created from a snapshot.
There is better news when updating an existing instance, since we can disable backups as part of the ModifyDBInstance request:
https://rds.amazonaws.com/
?Action=ModifyDBInstance
&DBInstanceIdentifier=mydbinstance
&BackupRetentionPeriod=0
Of course this still suffers from the loss of backups; however, my original purpose was to be able to create and modify snapshots of production databases, use them for a short period of time (hours), and then throw them away. Avoiding extraneous backup creation reduces overhead in this process.
Hopefully this information is useful to someone else!
If you create your RDS instance with Terraform using,
source = "github.com/terraform-aws-modules/terraform-aws-rds.git"
Although you must still set for example,
maintenance_window = "Mon:00:00-Mon:03:00"
backup_window = "03:00-06:00"
You can set
skip_final_snapshot= true
And the snapshot won't be created.
Shlomi