This section explains how to migrate Cloud DB for MSSQL running in NAVER Cloud Platform's Classic environment to a VPC environment.
The following topics are covered:
- Create Classic Path Service
- Create a backup server
- Database backup
- Configure VPC peering
- Create a Cloud DB for MSSQL for migration
- Database and SID issues troubleshooting

Follow the steps below in order.
Create Classic Path Service
Create a Classic Path Service to transfer data between the Classic and VPC environments.
Create a VPC for Classic Path
First, create a dedicated VPC to configure the Classic Path service.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Networking > VPC > VPC Management. - Click the [Create VPC] button and enter the following information:
- VPC name: name of the VPC to be created
- IP address range: 10.36.192.0/19 (CIDR band dedicated to the Classic Path VPC)
- Type: NORMAL
- After entering the information, click the [Create] button.
Create Classic Path
Create a Classic Path to connect the Classic and VPC environments.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Networking > Classic Path. - Click the [Create Classic Path] button and enter the following information:
- Classic Path name: name of the Classic Path to be created
- VPC: VPC created above
- Note: memo related to the Classic Path. To edit it, click the [Edit] button.
- After entering the information, click the [Create] button.
Create subnet
Create an additional subnet in the VPC dedicated to the Classic Path you just created.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> VPC > Subnet Management. - Click the [Create subnet] button and enter the following information:
- Subnet name: name of the subnet.
- VPC: VPC created in Classic Path.
- IP address range: the subnet's IP address range.
- Available zone: available zone in which the subnet is placed.
- Network ACL: network ACL applied to the subnet.
- Internet gateway exclusivity: indicates whether the subnet is connected to the internet. Y is displayed for public subnet, and N is displayed for private subnet.
- After entering the information, click the [Create] button.
Create a backup server
Create an application server that temporarily stores backup files and is used for restoration operations.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Server > Server > Create server. - Set the items below in order on the Set server tab.
- VPC: VPC created in Classic Path.
- Subnet: select a subnet to be used when accessing VPC.
- Server created: number of servers to be created.
- Server name: name of the server to be created.
- Public IP: select [Assign new public IP] if remote access is required.
- Note: memo related to the server. To edit it, click the [Edit] button.
Set disk capacity
Adjust the disk size as needed for the backup server.
- In the Set storage page, confirm or modify the following information:
- Storage name: name of the storage you want to use
- Storage type: type of storage you want to use
- Snapshot name: automatically set to the name chosen when creating
- Size: 100 GB or more is recommended. This depends on the backup volume.
- Storage type: type of Block Storage to be used
- IOPS: use the default value or set it according to performance needs.
If you need additional disks besides the default ones, you can set them by clicking the [Add storage] button.
Create a backup folder and enable sharing
Create a shared folder on your server for backups and grant Everyone permission to store MSSQL backup files in it.
-
Select a folder to use for backups.

-
Right-click the folder you created and open the [backup Properties] window.

-
Select [Sharing] from the top tab and click the [Share…] button.
-
When the Choose people to share with window appears, select Everyone from the drop-down menu, and click the [Add] button.
-
Change the Permission Level for Everyone to Read/Write.
-
Click the [Share] button at the bottom to share.
-
Confirm the Network Path to be used for future SQL Server backups.
-
Click the [Close] button to finish.
The network path is used as the TO DISK path for MSSQL BACKUP DATABASE commands.
Turn off the password protected sharing
Turn off the password protected sharing and public folder sharing settings to allow access to the backup folder.

- From the application server, go to Control Panel > Network and Internet > Network and Sharing Center > Advanced sharing settings.
- Expand the All Networks section and configure the following items:
- Public folder sharing: select Turn off Public folder sharing.
- Password protected sharing: select Turn off password protected sharing.
- When you have finished setting up the options, click the [Save changes] button.
Check the Classic DB Server information
Check the Cloud DB for MSSQL instance information of the Classic environment to be backed up.
- In the Classic environment of the NAVER Cloud Platform console, navigate to
> Services > Database > Cloud DB for MSSQL > DB Server.

- Select the target instance from the created DB server list.
- Ensure that it is in the same network band as the migration target.
Add ACG rules to allow access to Classic DB
If you need direct access to the Classic DB server from the application server, manually add an access-allow rule to the ACG.
- Click the [View rules] button next to the name of the DB server ACG that you checked above.

- In the Set ACG rule window, enter the following items:
- Protocol: TCP
- Access source: public IP address of the application server. You can also enter it automatically by clicking the [myIP] button.
- Allowed port: 1433
- Note: memo related to the ACG rule. To edit it, click the [Edit] button.
- Click the [Add] button, and then click the [Apply] button to save the settings.
Only set this if the application server needs to connect directly to the Classic DB.
Database backup
Back up data to a shared folder on the application server for backups created in the existing Classic DB.
Prepare a Classic Cloud DB for MSSQL database for migration
Create a database to be used in the Classic environment for backup and migration purposes.

- After running SQL Server Management Studio (SSMS), enter the following information to connect to the Classic Cloud DB for MSSQL:
- Server type: database engine
- Server name: DB server information
- Authentication: SQL server authentication
- Login: ID of the DB account
- Password: password of the DB account
- After connecting, create a test table as shown in the example below.

USE cpathdb1
GO
CREATE TABLE tblx (
idx INT IDENTITY(1,1)
)
GO
INSERT INTO tblx DEFAULT VALUES
GO 2
SELECT * FROM tblx
GO
- Check if the data is displayed correctly on the Results tab.
Add a CLASSICPATH route in the VPC route table
Add a CLASSICPATH route entry to communicate with the Classic environment.
-
From NAVER Cloud Platform console, click VPC > Route Table.

-
Select the desired route table for the public subnet and click the [Set routes] button.

- Click the [Create] button and enter the following values:
- Destination: 10.0.0.0/8
- Target type: CLASSICPATH
- Target name: name of the Classic Path you set
- When you are finished, click [OK] or [Apply] to save the settings.
Set the ACG for the backup server
Modify the ACG rule to allow the MSSQL server to access the shared folder on the backup server.
- Check the ACG applied to the application server for backup.
- Click the [View rules] button for the ACG in the console.

- On the [Inbound rules] tab, ensure the following rules are included:
- Protocol: TCP
- Access source: 10.0.0.0/8
- Allowed port: 445
- If there is no such rule, apply the same item and click the [OK] > [Apply] button in order.
Cloud DB for MSSQL backup
Back up the database in the classic environment to a shared folder on the application server.
- Connect to SQL Server Management Studio (SSMS).

- Enter the queries shown in the example below and execute them sequentially.
CREATE TABLE tblx (
idx INT IDENTITY (1,1)
);
GO
INSERT INTO tblx DEFAULT VALUES;
GO 2
SELECT * FROM tblx;
GO
BACKUP DATABASE cpathdb1
TO DISK = '\\10.36.192.6\backup\cpathdb1.full'
WITH INIT;
GO
- On the Messages tab at the bottom, check if the completion time is displayed along with the "BACKUP DATABASE successfully processed..." message.
Check the SID value of the Classic Cloud DB for MSSQL administrator account
Check the SID value of Classic DB to create the same login account in the environment to be restored.
- Connect to SQL Server Management Studio (SSMS).

- Enter and execute the query below.
SELECT SID
FROM master.sys.sql_logins
WHERE name = 'testadmin'
Configure VPC peering
Configure peering to enable communication between the Classic Path VPC and the running VPC.
Check the information of the Classic Path VPC and the running VPC
Check the CIDR bands of the Classic Path VPC and the migration target VPC.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Networking > VPC > VPC Management.

-
Check the following items:
- CIDR of the Classic Path dedicated VPC
- CIDR of the running VPC
-
In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Networking > VPC > Subnet Management.

- Check the following items:
- Subnet of the Classic Path VPC
- Subnet of the running VPC
If the CIDR bands overlap, you cannot configure VPC peering.
Delete the CLASSICPATH route from the route table
Delete the CLASSICPATH route for the VPC peering route operation.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Networking > VPC > Route Table.

- Select the route table for the public subnet where the route to be deleted is set and click the [Set routes] button.
- Find a route entry that meets the following conditions and click the [Delete] button:
- Destination: IP address belonging to the Classic Path environment
- Target type: CLASSICPATH
- Target name: name of the Classic Path you created
- Click the [Apply] button to save the changes.
Configure VPC peering between the Classic Path VPC and the user VPC
VPC peering must be configured in both directions for communication between the Classic Path VPC and the user VPC. Each VPC must be in a different CIDR range, and two peerings must be created, with the requester-receiver role reversed for one of them.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Networking > VPC > VPC Peering.

-
Click the [Create VPC peering] button and enter the following information:
- Requesting VPC: Classic Path VPC (
vpccpath) - Accepting VPC: user VPC (
mssqlvpc) - Requesting VPC IP address range:
10.36.192.0/19 - Accepting VPC IP address range:
10.0.0.0/16
- Requesting VPC: Classic Path VPC (
-
Create one more peering in the opposite direction.
- Requesting VPC: user VPC (
mssqlvpc) - Accepting VPC: Classic Path VPC (
vpccpath) - Requesting VPC IP address range:
10.0.0.0/16 - Accepting VPC IP address range:
10.36.192.0/19
- Requesting VPC: user VPC (
-
Check if both peers have a status of "Running."
Set route table
Once peering is configured successfully, add a route setting to each VPC that specifies the other VPC as the destination.
-
Classic Path VPC → User VPC route setting
- Go to VPC > Route Table.
- Select the
vpccpath-default-public-tableitem. - In the Routes tab, check if the following entries exist:
- Destination:
10.0.0.0/16 - Target type:
VPCPEERING - Target name:
classicpathvpc2vpc
- Destination:
- If the route does not exist, add it manually.
-
User VPC → Classic Path VPC route setting
- Select the route table of the user VPC in the same way (
mssqlvpc-default-public-table). - In the Routes tab, check if the following entries exist:
- Destination:
10.36.192.6/32 - Target type:
VPCPEERING - Target name:
vpc2classicpathvpc
- Destination:
- Select the route table of the user VPC in the same way (
Create a Cloud DB for MSSQL for migration
Create a Cloud DB for MSSQL instance in advance in the VPC environment for backup data migration.
VPC Cloud DB for MSSQL ACG settings
Check the ACG settings so that the Cloud DB for MSSQL instance in the VPC environment can access the backup server's shared folder.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Database > Cloud DB for MSSQL > DB Server > DB Server 상세 화면 > ACG > [View rules]. - Check if the following ACG rule is included:
- Outbound rule
- Protocol:
TCP - Destination:
10.36.192.6/32 - Allowed port:
445
- Protocol:
- Outbound rule
Check the VPC Cloud DB for MSSQL server
Check the MSSQL Cloud DB instance in the VPC environment to which you want to migrate your backup files.
- In the VPC environment of the NAVER Cloud Platform console, navigate to
> Services > Database > Cloud DB for MSSQL > DB Server.

- Select the target DB server and check the following items:
- DB service name: service name of the DB to be restored
- DB engine version: engine version of the DB to be restored
- VPC: name of the VPC to which the DB to be restored is connected
- Subnet: name of the subnet where the DB to be restored is located
- Access port:
1433 - ACG name: name of the access control group connected to the DB instance
Database and SID issues troubleshooting
Restore the data backed up to the application server in the Classic Path VPC to the Cloud DB for MSSQL instance in the VPC environment.
Restore the database using a backup file
Perform the restore by referencing the backup file in the shared folder path of the Classic Path VPC connected through peering.
- Run SQL Server Management Studio (SSMS) and connect to the MSSQL server in the VPC environment.
- Run the query below to perform the restore.

RESTORE DATABASE cpathdb1
FROM DISK = '\\10.36.192.6\backup\cpathdb1.full'
WITH REPLACE;
- Once the restore process is complete, the phrases "Processed" and "RESTORE DATABASE successfully" will be displayed in the output message.
SID-based account creation and login verification
Access to the restored database may be restricted if the user account is not created with the same SID as the existing Classic environment. To avoid this issue, create a login account using the SID value from the existing Classic DB, then check to see if the account has access.
- Connect to the master database in SQL Server Management Studio (SSMS).
- Run the syntax below.

CREATE LOGIN AServerAdmin
WITH PASSWORD='P@ssw0rd'
, SID=0x3D75220DEFFB564588417C6A6EBC7BB7
, DEFAULT_DATABASE=[master]
, CHECK_POLICY=OFF
, CHECK_EXPIRATION=OFF
GO
- After executing the command, check if the message "Command completed" appears.
- Then, open the Connect to server window in SSMS.

- Enter the following items and connect to the server:
- Server name: DB server address of the VPC environment
- Authentication: SQL server authentication
- Login: user account ID
- Password: user password
To ensure proper integrations with database users and normal access, you must assign the same SID as the account used in the Classic environment.
Grant the VPC Cloud DB for MSSQL console user the DB_OWNER privilege of the restored database
Link an existing console user account to the restored database and grant it the db_owner privilege.

- Connect to the restored database in SQL Server Management Studio (SSMS).
- Run the SQL statement below to create the console user account and assign the
db_ownerrole to it.
USE cpathdb1
GO
CREATE USER testadmin FOR LOGIN testadmin
GO
ALTER ROLE [db_owner] ADD MEMBER testadmin
GO
If the query runs successfully, the console user account testadmin will have full privileges on the cpathdb1 database.
Check the restored data in the restored database using the Console Admin account
After completing the SID restoration and authorization settings, connect to the database using the console user account to confirm that the restoration was successful.

- In SSMS, connect to the
cpathdb1database with the console user account. - Run the following query to verify that the data has been successfully restored:
SELECT * FROM tblx
If the data is not retrieved, recheck the login SID match or user authorization status.
Once the restore and access permissions are complete, the data entered prior to the restore should be displayed normally in the tblx table.