Creating a Protected Group for IBM DB2 Databases

This section describes how to create a protected group at the production site for IBM DB2 databases that need DR protection. After the protected group is created, the system automatically matches suitable protection policies for the protected group.

Prerequisites

Context

In HyperMetro (SAN) and backup (SAN) scenarios, storage LUNs used by protected objects in a protected group must reside in a same HyperMetro consistency group, and the HyperMetro consistency group only have these LUNs.

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 the 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 policy based on your data protection solution.
      • When the HyperMetro (SAN) and Backup (SAN) DR technology is used, select HyperMetro and Backup:HyperMetro data center 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. When the HyperMetro (SAN) and Backup (SAN) DR technology is used, click Set to set the protection policy for the protected group.

      When a protected object is added to multiple protected groups, ensure that the time policies do not overlap each other. Otherwise, applications cannot be frozen or unfrozen when these time policies are executed.

      1. Select a 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.
      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 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.
      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 Reservation Policy tab. Set Latest duplicate and the duplicate retention policy. Table 2 describes related parameters.

        Table 2 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.
      5. 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.

      6. 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 HyperMetro (SAN), HyperMetro (SAN) and 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

Parent topic: Creating a Protected Group
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