Creating a Protected Group for IBM DB2 Databases

Prerequisites

• At least one production site has been created.
• Hosts or host groups and storage devices for host applications have been added to the production site.

Context

One protected group can only contain IBM DB2 databases that belong to the same instance.

The protected objects belonging to one protected group reside on the same storage device. Each protected object occupies independent storage LUNs or volumes.

Procedure

1. In the menu bar, Choose Protection.
2. Click Create.
3. Select a protected object.
   1. Set Production Site and Production Host(Group).
   2. In the Available Database area, select the databases that you want to protect.
   3. In the Verification dialog box that is displayed, enter necessary authentication information and click OK.

4. Click Next.
5. Set a protection policy.
   1. On the Protection Policy page, the system automatically matches supported protection policies. Select a protection policy based on your data protection solution.
      • When the synchronous Clone (SAN) DR technology is used, select Clone:Backup protection solution.
      • When the synchronous Backup (SAN) DR technology is used, select Backup:Backup protection solution.
      

      • If there are suitable protection policies, you can select a protection policy based on your data protection solution and modify the time policy of the protection policy.
      • If there is no suitable protection policy, check whether the storage devices used by protected objects have been configured as planned. If the storage devices have not been configured, configure them as planned. After configuration, perform the following operations: On the menu bar, select Resources. Select a node under the management server. In the site node, click Storage, in the line where the storage device resides, click Refresh to refresh the storage device information under the site. Then, recreate the protected group.
   2. Click Set to set the protection policy for the protected group.
      • For Clone:Backup protection solution:
        1. In the Protection Policy area, click Set to set the protection policy for the protected group.
        2. Click the Scheduling Policy tab. In the Time Policy area, set the time policy for the protected group. Table 1 lists related parameters.

           

           Table 1 Time policies

           Time Policy	Description
           On-demand scheduling	Manually starts protection tasks.
           Period-based scheduling	Automatically starts protection tasks based on a period set by the system. NOTE: To ensure data consistency, the execution timetable for a protected group policy template must be set. You are advised to set the execution time to off-peak hours. Tasks can be executed at multiple time points of a day, a week, or a month. Alternatively, at a specific time segment of a day, a week, or a month with a fixed frequency. It is recommended that the starting time of the validate period is set to a time later than the completion of the initial synchronization. If daylight saving time (DST) is enabled on the eReplication management server, a DR protection task whose trigger time point falls within the DST shift period cannot be executed at the scheduled time. Details are as follows: (UTC-08:00) Pacific Time (United States and Canada) is used as an example. The DST starts at 2016-03-12 02:00:00, and ends at 2016-11-06 02:00:00. If the start time of the protection policy falls within the first hour (2016-03-12 02:00:00 to 03:00:00) after the DST starts, for example, 2016-03-12 02:30:00, the protection group will be automatically executed with a delay of one hour, that is 2016-03-12 03:30:00. If the start time of the protection policy falls with the last hour (2016-11-06 01:00:00 to 02:00:00) before the DST ends, for example, 2016-11-06 01:30:00, the protection group will be executed after the DST ends for half an hour.

        3. When the Scheduling Policy is set to Period-based scheduling, in the Expected RPO area, if you select Enable PRO Requirement Satisfaction Check, the actual RPO is check against the configured RPO. If the actual RPO exceeds the expected RPO, the system generates an alarm, indicating that the RPO requirement is not satisfied.

           

           Expected RPO can be set to 0-31 days, 0-23 hours, and 5-59 minutes.

           

           If days and hours are not set, the Expected RPO is 15 minutes by default.

        4. Click the Consistency Policy tab, select Enable hot backup mode and Configure Min. Archive Space Threshold, and set the threshold.

           To enable the hot backup mode, the archive log mode must be enabled for the database. Otherwise, protected groups cannot be executed after the hot backup mode is enabled. If you do not select Enable hot backup mode, when protected groups are executed based on specified policies, the database remains online but the hot backup mode is not enabled. In this case, data consistency totally relies on storage devices' ability to ensure consistency.

           

           If you select Enable hot backup mode, when protected groups are executed based on specified policies, the database remains online. Before storage array-based replication or taking snapshots, the system will set the database to the hot backup mode to ensure data consistency. After the hot backup mode is enabled, database services may stop because the archive log space is used up during DR execution. Therefore, you are advised to select Configure Min. Archive Space and configure it after enabling the hot backup mode. After the archive log space threshold is specified, DR execution will fail if the archive log space is lower than the specified threshold.

        5. In the Storage Configuration area, select the resource pool configuration as show in Table 2.

           Table 2 Resource pool configuration

           Configuration	Description
           Default configuration	Please select or create the resource pool at first, the system will establish clone replationship based on LUNs in resource pool. If a data protection service (for example, snapshots) has been created for a matched resource, the clone relationship may fail to be created. The protected object (clone primary LUN) has a one-to-one relationship with the matched resource (clone secondary LUN).
           Manual configuration	Manually select the resource pool, if not, click Create, the system will establish clone replationship based on LUNs in resource pool. The protected object (clone primary LUN) has a one-to-one relationship with the matched resource (clone secondary LUN).

        6. Click OK.
      • For Backup:Backup protection solution:
        1. In the Quick Backup area of Protection Policy, click Set to set the protection policy for the protected group.
        2. Click Enable Quick Backup and select Backup Type.
           • Snapshot: The read and write permissions of the generated snapshot are readable and writable.
           • HyperCDP: The read and write permissions of the generated snapshot are readable.
           

           • If you have purchased the HyperCDP license, HyperCDP is recommended. HyperCDP provides high-density protection, ultra-large specifications, and lossless performance.
           • Create a second-level protected group. BCManager creates a scheduled plan on the storage array. The scheduled plan can be managed only by BCManager. You cannot delete the scheduled plan from the storage array.
        3. Click the Scheduling Policy tab. In the Time Policy area, set the time policy for the protected group. Table 3 lists related parameters.

           

           Table 3 Time policies

           Time Policy	Description
           On-demand scheduling	Manually starts protection tasks.
           Period-based scheduling	Automatically starts protection tasks based on a period set by the system. NOTE: To ensure data consistency, the execution timetable for a protected group policy template must be set. You are advised to set the execution time to off-peak hours. Tasks can be executed at multiple time points of a second, a minute, an hour, a day, a week, or a month. Alternatively, at a specific time segment of a second, a minute, an hour, a day, a week, or a month with a fixed frequency. When Backup Type is set to Snapshot and Time Period is set to Second, the minimum interval for executing protected groups is 30 seconds. When Backup Type is set to HyperCDP and Time Period is set to Second, the minimum interval for executing protected groups is as follows: OceanStor Dorado V3: 10 seconds OceanStor Dorado 6.x: 3 seconds It is recommended that the starting time of the validate period is set to a time later than the completion of the initial synchronization. If daylight saving time (DST) is enabled on the eReplication management server, a DR protection task whose trigger time point falls within the DST shift period cannot be executed at the scheduled time. Details are as follows: (UTC-08:00) Pacific Time (United States and Canada) is used as an example. The DST starts at 2016-03-12 02:00:00, and ends at 2016-11-06 02:00:00. If the start time of the protection policy falls within the first hour (2016-03-12 02:00:00 to 03:00:00) after the DST starts, for example, 2016-03-12 02:30:00, the protection group will be automatically executed with a delay of one hour, that is 2016-03-12 03:30:00. If the start time of the protection policy falls with the last hour (2016-11-06 01:00:00 to 02:00:00) before the DST ends, for example, 2016-11-06 01:30:00, the protection group will be executed after the DST ends for half an hour.

        4. When the Scheduling Policy is set to Period-based scheduling, in the Expected RPO area, if you select Enable PRO Requirement Satisfaction Check, the actual RPO is check against the configured RPO. If the actual RPO exceeds the expected RPO, the system generates an alarm, indicating that the RPO requirement is not satisfied.

           

           Expected RPO can be set to 0-31 days, 0-23 hours, and 5-59 minutes.

           

           If days and hours are not set, the Expected RPO is 15 minutes by default.

        5. Click the Reservation Policy tab. Set Latest duplicate and the duplicate retention policy. Table 4 describes related parameters.
           

           Table 4 Retention policies

           Retention Policy	Description
           Latest duplicate	The number of duplicates cannot exceed the maximum number of snapshots that can be taken for a storage resource such as a LUN or file system.
           Duplicate retention	The duplicate retention policy defines the retention policy of duplicates generated during the protected group protection. When the system starts duplicate maintenance, expired and invalid duplicates will be deleted based on the duplicate retention policy. By default, the time to maintain duplicates is the 39th minute of every hour. You can set the minimum number of duplicates to be retained. The system will not delete valid duplicates until the number of invalid duplicates exceeds the minimum number of duplicates you set. The value range for a daily policy is 0–365. The default value is 0, meaning to retain no duplicates. The value range for a weekly policy is 0–52. The default value is 0, meaning to retain no duplicates. The value range for a monthly policy is 0–60. The default value is 0, meaning to retain no duplicates. When determining the number of retained duplicates, consider the following: Data importance and DR requirements. If data of the latest five months must be retained, you are advised to set the retention period by month. Available storage space of a storage device. If the available space of a storage device is sufficient, you are advised to retain more duplicates that are more important. NOTE: For example, if the current time is 2017/4/11 08:40:00, configure the protected group as following: Set the execution policy to be performed at every hour exactly. Set the retention policy to keep five latest duplicates, three daily duplicates, two weekly duplicates, and one monthly duplicate. If the protected group is under the automatically scheduled protection for a long time, the duplicates retained are as follows after the duplicate maintenance is complete at the current time: Latest duplicates were generated at: 2017-04-11 08:00, 2017-04-11 07:00, 2017-04-11 06:00, 2017-04-11 05:00, and 2017-04-11 04:00. Daily duplicates are generated at: 2017-04-10 23:00, 2017-04-09 23:00, and 2017-04-08 23:00. Weekly duplicates were generated at: 2017-04-09 23:00 and 2017-04-02 23:00. The monthly duplicate was generated at: 2017-03-31 23:00. NOTE: If the duplicate maintenance is not triggered, or daily, weekly, or monthly duplicate retention is configured, the number of retained duplicates may exceed the number of latest duplicates being retained. If the scheduling time period is second, the copy retention policy is automatically executed by the storage device.

        6. Click the Consistency Policy tab and select Quiesce database.

           Consistency between databases is ensured by hanging write I/Os. After write I/Os are hung, the storage device starts replication or generates snapshots. Afterwards, the eReplication Agent renews write I/Os.

        7. Click OK.

6. Click Next.
7. Set Name and Description of the protected group.
   • Name: contains 4 to 32 characters, including letters, digits, underscores (_), and hyphens (-), but cannot start with a hyphen (-).
   • Description: contains 0 to 255 characters.

8. When the Backup (SAN) DR technology is used, if you do not want to manually create a recovery plan for the protected group, select Automatically create a recovery plan after creating protected groups at the lower left corner.
9. Click Finish.
10. Click OK.

Related Operations

• If the protected objects of a protected group or their used storage devices change. On the menu bar, select Resources. And refresh resources or storage devices where the protected objects reside. Then go to the protected group page and refresh protected objects of the protected group by clicking More > Refresh. After the command for refreshing information is sent, you can view details about the command execution in Background Task.
  

  If a recovery plan has been created for a protected group, you can refresh protected objects only when the recovery plan status is Ready, Clear completed, Rollback completed, or Reprotection completed.

• To ensure that information about protected groups is refreshed successfully, you must refresh information about storage devices and hosts at both the production site and DR site.
  

  If a protected group uses backup (SAN), a snapshot copy being used by a recovery plan cannot be deleted. To delete such a snapshot copy, wait until the recovery plan finishes clearing.