Backing up and restoring an Amazon RDS Custom for SQL Server DB instance - Amazon Relational Database Service

Backing up and restoring an Amazon RDS Custom for SQL Server DB instance

Like Amazon RDS, RDS Custom creates and saves automated backups of your RDS Custom for SQL Server DB instance during the backup window of your DB instance. You can also back up your DB instance manually.

The procedure is identical to taking a snapshot of an Amazon RDS DB instance. The first snapshot of an RDS Custom DB instance contains the data for the full DB instance. Subsequent snapshots are incremental.

Restore DB snapshots using either the AWS Management Console or the AWS CLI.

Creating an RDS Custom for SQL Server snapshot

RDS Custom for SQL Server creates a storage volume snapshot of your DB instance, backing up the entire DB instance and not just individual databases. When you create a snapshot, specify which RDS Custom for SQL Server DB instance to back up. Give your snapshot a name so you can restore from it later.

When you create a snapshot, RDS Custom for SQL Server creates an Amazon EBS snapshot for every volume attached to the DB instance. RDS Custom for SQL Server uses the EBS snapshot of the root volume to register a new Amazon Machine Image (AMI). To make snapshots easy to associate with a specific DB instance, they're tagged with DBSnapshotIdentifier, DbiResourceId, and VolumeType.

Creating a DB snapshot results in a brief I/O suspension. This suspension can last from a few seconds to a few minutes, depending on the size and class of your DB instance. The snapshot creation time varies with the size of your database. Because the snapshot includes the entire storage volume, the size of files, such as temporary files, also affects snapshot creation time. To learn more about creating snapshots, see Creating a DB snapshot.

Create an RDS Custom for SQL Server snapshot using the console or the AWS CLI.

To create an RDS Custom snapshot

  1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

  2. In the navigation pane, choose Databases.

  3. In the list of RDS Custom DB instances, choose the instance for which you want to take a snapshot.

  4. For Actions, choose Take snapshot.

    The Take DB snapshot window appears.

  5. For Snapshot name, enter the name of the snapshot.

  6. Choose Take snapshot.

You create a snapshot of an RDS Custom DB instance by using the create-db-snapshot AWS CLI command.

Specify the following options:

  • --db-instance-identifier – Identifies which RDS Custom DB instance you are going to back up

  • --db-snapshot-identifier – Names your RDS Custom snapshot so you can restore from it later

In this example, you create a DB snapshot called my-custom-snapshot for an RDS Custom DB instance called my-custom-instance.

For Linux, macOS, or Unix:

aws rds create-db-snapshot \ --db-instance-identifier my-custom-instance \ --db-snapshot-identifier my-custom-snapshot

For Windows:

aws rds create-db-snapshot ^ --db-instance-identifier my-custom-instance ^ --db-snapshot-identifier my-custom-snapshot

Restoring from an RDS Custom for SQL Server DB snapshot

When you restore an RDS Custom for SQL Server DB instance, you provide the name of the DB snapshot and a name for the new instance. You can't restore from a snapshot to an existing RDS Custom DB instance. A new RDS Custom for SQL Server DB instance is created when you restore.

The restore process differs in the following ways from restore in Amazon RDS:

  • Before restoring a snapshot, RDS Custom for SQL Server backs up existing configuration files. These files are available on the restored instance in the directory /rdsdbdata/config/backup. RDS Custom for SQL Server restores the DB snapshot with default parameters and overwrites the previous database configuration files with existing ones. Thus, the restored instance doesn't preserve custom parameters and changes to database configuration files.

  • The restored database has the same name as in the snapshot. You can't specify a different name.

To restore an RDS Custom DB instance from a DB snapshot

  1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

  2. In the navigation pane, choose Snapshots.

  3. Choose the DB snapshot that you want to restore from.

  4. For Actions, choose Restore snapshot.

  5. On the Restore DB instance page, for DB instance identifier, enter the name for your restored RDS Custom DB instance.

  6. Choose Restore DB instance.

You restore an RDS Custom DB snapshot by using the restore-db-instance-from-db-snapshot AWS CLI command.

If the snapshot you are restoring from is for a private DB instance, make sure to specify both the correct db-subnet-group-name and no-publicly-accessible. Otherwise, the DB instance defaults to publicly accessible. The following options are required:

  • db-snapshot-identifier – Identifies the snapshot from which to restore

  • db-instance-identifier – Specifies the name of the RDS Custom DB instance to create from the DB snapshot

  • custom-iam-instance-profile – Specifies the instance profile associated with the underlying Amazon EC2 instance of an RDS Custom DB instance.

The following code restores the snapshot named my-custom-snapshot for my-custom-instance.

For Linux, macOS, or Unix:

aws restore-db-instance-from-db-snapshot \ --db-snapshot-identifier my-custom-snapshot \ --db-instance-identifier my-custom-instance \ --custom-iam-instance-profile AWSRDSCustomInstanceProfileForRdsCustomInstance \ --no-publicly-accessible

For Windows:

aws restore-db-instance-from-db-snapshot ^ --db-snapshot-identifier my-custom-snapshot ^ --db-instance-identifier my-custom-instance ^ --custom-iam-instance-profile AWSRDSCustomInstanceProfileForRdsCustomInstance ^ --no-publicly-accessible

Restoring an RDS Custom for SQL Server instance to a point in time

You can restore a DB instance to a specific point in time (PITR), creating a new DB instance. To support PITR, your DB instances must have backup retention set to a nonzero value.

The latest restorable time for an RDS Custom for SQL Server DB instance depends on several factors, but is typically within 5 minutes of the current time. To see the latest restorable time for a DB instance, use the AWS CLI describe-db-instances command and look at the value returned in the LatestRestorableTime field for the DB instance. To see the latest restorable time for each DB instance in the Amazon RDS console, choose Automated backups.

You can restore to any point in time within your backup retention period. To see the earliest restorable time for each DB instance, choose Automated backups in the Amazon RDS console.

For general information about PITR, see Restoring a DB instance to a specified time.

PITR considerations for RDS Custom for SQL Server

In RDS Custom for SQL Server, PITR differs in the following important ways from PITR in Amazon RDS:

  • PITR only restores the databases in the DB instance. It doesn't restore the operating system or files on the C: drive.

  • For an RDS Custom for SQL Server DB instance, a database is backed up automatically and is eligible for PITR only under the following conditions:

    • The database is online.

    • Its recovery model is set to FULL.

    • It's writable.

    • It has its physical files on the D: drive.

    • It's not listed in the rds_pitr_blocked_databases table. For more information, see Making databases ineligible for PITR.

  • RDS Custom for SQL Server allows up to 5,000 databases per DB instance. However, the maximum number of databases restored by a PITR operation for an RDS Custom for SQL Server DB instance is 100. The 100 databases are determined by the order of their database ID.

    Other databases that aren't part of PITR can be restored from DB snapshots, including the automated backups used for PITR.

  • Adding a new database, renaming a database, or restoring a database that is eligible for PITR initiates a snapshot of the DB instance.

  • Restored databases have the same name as in the source DB instance. You can't specify a different name.

  • AWSRDSCustomSQLServerIamRolePolicy requires new permissions. For more information, see Add an access policy to AWSRDSCustomSQLServerInstanceRole.

  • Time zone changes aren't supported for RDS Custom for SQL Server. If you change the operating system or DB instance time zone, PITR (and other automation) doesn't work.

Making databases ineligible for PITR

You can specify that certain RDS Custom for SQL Server databases aren't part of automated backups and PITR. To do this, put their database_id values into a rds_pitr_blocked_databases table. Use the following SQL script to create the table.

To create the rds_pitr_blocked_databases table

  • Run the following SQL script.

    create table msdb..rds_pitr_blocked_databases ( database_id INT NOT NULL, database_name SYSNAME NOT NULL, db_entry_updated_date datetime NOT NULL DEFAULT GETDATE(), db_entry_updated_by SYSNAME NOT NULL DEFAULT CURRENT_USER, PRIMARY KEY (database_id) );

For the list of eligible and ineligible databases, see the RI.End file in the RDSCustomForSQLServer/Instances/DB_instance_resource_ID/TransactionLogMetadata directory in the Amazon S3 bucket do-not-delete-rds-custom-$ACCOUNT_ID-$REGION-unique_identifier. For more information about the RI.End file, see Transaction logs in Amazon S3.

Transaction logs in Amazon S3

The backup retention period determines whether transaction logs for RDS Custom for SQL Server DB instances are automatically extracted and uploaded to Amazon S3. A nonzero value means that automatic backups are created, and that the RDS Custom agent uploads the transaction logs to S3 every 5 minutes.

Transaction log files on S3 are encrypted at rest using the AWS KMS key that you provided when you created your DB instance. For more information, see Protecting data using server-side encryption in the Amazon Simple Storage Service User Guide.

The transaction logs for each database are uploaded to an S3 bucket named do-not-delete-rds-custom-$ACCOUNT_ID-$REGION-unique_identifier. The RDSCustomForSQLServer/Instances/DB_instance_resource_ID directory in the S3 bucket contains two subdirectories:

  • TransactionLogs – Contains the transaction logs for each database and their respective metadata.

    The transaction log file name follows the pattern yyyyMMddHHmm.database_id.timestamp, for example:

    202110202230.11.1634769287

    The same file name with the suffix _metadata contains information about the transaction log such as log sequence numbers, database name, and RdsChunkCount. RdsChunkCount determines how many physical files represent a single transaction log file. You might see files with suffixes _0001, _0002, and so on, which mean the physical chunks of a transaction log file. If you want to use a chunked transaction log file, make sure to merge the chunks after downloading them.

    Consider a scenario where you have the following files:

    • 202110202230.11.1634769287

    • 202110202230.11.1634769287_0001

    • 202110202230.11.1634769287_0002

    • 202110202230.11.1634769287_metadata

    The RdsChunkCount is 3. The order for merging the files is the following: 202110202230.11.1634769287, 202110202230.11.1634769287_0001, 202110202230.11.1634769287_0002.

  • TransactionLogMetadata – Contains metadata information about each iteration of transaction log extraction.

    The RI.End file contains information for all databases that had their transaction logs extracted, and all databases that exist but didn't have their transaction logs extracted. The RI.End file name follows the pattern yyyyMMddHHmm.RI.End.timestamp, for example:

    202110202230.RI.End.1634769281

You can restore an RDS Custom for SQL Server DB instance to a point in time using the AWS Management Console, the AWS CLI, or the RDS API.

To restore an RDS Custom DB instance to a specified time

  1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

  2. In the navigation pane, choose Automated backups.

  3. Choose the RDS Custom DB instance that you want to restore.

  4. For Actions, choose Restore to point in time.

    The Restore to point in time window appears.

  5. Choose Latest restorable time to restore to the latest possible time, or choose Custom to choose a time.

    If you chose Custom, enter the date and time to which you want to restore the instance.

    Times are shown in your local time zone, which is indicated by an offset from Coordinated Universal Time (UTC). For example, UTC-5 is Eastern Standard Time/Central Daylight Time.

  6. For DB instance identifier, enter the name of the target restored RDS Custom DB instance. The name must be unique.

  7. Choose other options as needed, such as DB instance class.

  8. Choose Restore to point in time.

You restore a DB instance to a specified time by using the restore-db-instance-to-point-in-time AWS CLI command to create a new RDS Custom DB instance.

Use one of the following options to specify the backup to restore from:

  • --source-db-instance-identifier mysourcedbinstance

  • --source-dbi-resource-id dbinstanceresourceID

  • --source-db-instance-automated-backups-arn backupARN

The custom-iam-instance-profile option is required.

The following command restores my-custom-instance to a new DB instance named my-restored-custom-instance, as of the specified time.

For Linux, macOS, or Unix:

aws rds restore-db-instance-to-point-in-time \ --source-db-instance-identifier my-custom-instance\ --target-db-instance-identifier my-restored-custom-instance \ --custom-iam-instance-profile AWSRDSCustomInstanceProfileForRdsCustomInstance \ --restore-time 2021-07-14T23:45:00.000Z

For Windows:

aws rds restore-db-instance-to-point-in-time ^ --source-db-instance-identifier my-custom-instance ^ --target-db-instance-identifier my-restored-custom-instance ^ --custom-iam-instance-profile AWSRDSCustomInstanceProfileForRdsCustomInstance ^ --restore-time 2021-07-14T23:45:00.000Z

Deleting an RDS Custom for SQL Server snapshot

You can delete DB snapshots managed by RDS Custom for SQL Server when you no longer need them. The deletion procedure is the same for both Amazon RDS and RDS Custom DB instances.

The Amazon EBS snapshots for the binary and root volumes remain in your account for a longer time because they might be linked to some instances running in your account or to other RDS Custom for SQL Server snapshots. These EBS snapshots are automatically deleted after they're no longer related to any existing RDS Custom for SQL Server resources (DB instances or backups).

To delete a snapshot of an RDS Custom DB instance

  1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

  2. In the navigation pane, choose Snapshots.

  3. Choose the DB snapshot that you want to delete.

  4. For Actions, choose Delete snapshot.

  5. Choose Delete on the confirmation page.

To delete an RDS Custom snapshot, use the AWS CLI command delete-db-snapshot.

The following option is required:

  • --db-snapshot-identifier – The snapshot to be deleted

The following example deletes the my-custom-snapshot DB snapshot.

For Linux, macOS, or Unix:

aws rds delete-db-snapshot \ --db-snapshot-identifier my-custom-snapshot

For Windows:

aws rds delete-db-snapshot ^ --db-snapshot-identifier my-custom-snapshot

Deleting RDS Custom for SQL Server automated backups

You can delete retained automated backups for RDS Custom for SQL Server when they are no longer needed. The procedure is the same as the procedure for deleting Amazon RDS backups.

To delete a retained automated backup

  1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

  2. In the navigation pane, choose Automated backups.

  3. Choose Retained.

  4. Choose the retained automated backup that you want to delete.

  5. For Actions, choose Delete.

  6. On the confirmation page, enter delete me and choose Delete.

You can delete a retained automated backup by using the AWS CLI command delete-db-instance-automated-backup.

The following option is used to delete a retained automated backup:

  • --dbi-resource-id – The resource identifier for the source RDS Custom DB instance.

    You can find the resource identifier for the source DB instance of a retained automated backup by using the AWS CLI command describe-db-instance-automated-backups.

The following example deletes the retained automated backup with source DB instance resource identifier custom-db-123ABCEXAMPLE.

For Linux, macOS, or Unix:

aws rds delete-db-instance-automated-backup \ --dbi-resource-id custom-db-123ABCEXAMPLE

For Windows:

aws rds delete-db-instance-automated-backup ^ --dbi-resource-id custom-db-123ABCEXAMPLE