🧩 ORA-19566: Exceeded Limit of Device Types Using Backup or Copy

 🧩 Introduction:

The ORA-19566 error appears during RMAN or user-managed backup operations when Oracle exceeds the configured limit of device types. This often happens if multiple channels or device types (like DISK and SBT) are used in the same job without proper configuration. Understanding and correcting the device configuration ensures smooth, efficient backups.

Causes:

1. More than one type of backup device (e.g., DISK and TAPE) used without explicit allocation.

2. RMAN channel configuration conflicts with default settings.

3. Misconfigured DEVICE TYPE parameter in RMAN.

4. RMAN job scripts mixing ALLOCATE CHANNEL and CONFIGURE CHANNEL for different devices.

5. Outdated or corrupted RMAN configuration metadata.

Example:

RMAN-03009: failure of backup command on ORA_DISK_1 channel

ORA-19566: exceeded limit of 1 device type for backup or copy

This error indicates RMAN tried to use more than one device type (e.g., DISK and TAPE) at the same time, which is not supported in a single backup operation.

Solution:

1. Check RMAN configuration:

Use the following command to list all configured channels:

RMAN> SHOW ALL;

Look for multiple device types such as DISK and SBT_TAPE.

2. Reconfigure device type:

If you only intend to use disk backups:

RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 2;

RMAN> CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '/u01/backups/%U';

3. Remove unused device types:

RMAN> CONFIGURE DEVICE TYPE SBT_TAPE CLEAR;

4. Avoid mixing device types:

When using ALLOCATE CHANNEL, ensure all channels are of the same type:

RUN {

    ALLOCATE CHANNEL c1 DEVICE TYPE DISK;

    BACKUP DATABASE;

    RELEASE CHANNEL c1;

}

5. Reset configuration if necessary:

If configurations are corrupted or unclear:

RMAN> CONFIGURE CLEAR;

Best Practices:

Always verify RMAN configurations before scheduling backups.

Use consistent DEVICE TYPE across all backup scripts.

Keep a backup of RMAN configuration for reference.

Use SHOW ALL regularly to ensure configurations remain clean and consistent.