Creating a Protected Group for LUNs

Prerequisites

• At least one production site has been created.
• At least one storage device has been added.
• LUNs in the backup (SAN) scenario must belong to the system vStore.

Context

Protected objects in a protected group must reside on the same storage device.

Procedure

1. In the menu bar, Choose Protection.
2. Click Create.
3. Select a protected object.
   1. Select Production Site and Disk Array.
   2. In LUN and Consistency Groups, select the protect object.
      • LUN

        If you want to protect one LUN only or multiple LUNs that reside in different remote replication consistency groups, set the protected object type to LUN.

      • Remote replication consistency group

        If you want to protect all LUNs of one remote replication consistency group, set the protected object type to Remote replication consistency group.

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. Click Set to set the protection policy for the protected group.
      

      For the HyperMetro and Backup:HyperMetro data center solution protection policy, you need to set scheduling policy, consistency policy and replication policy at the production end and the DR end.

      1. 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.

      2. 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.

      3. 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.

      4. If Enable consistency protection is selected, the system runs the application freezing script on a specific host (or host group) to ensure replica data consistency when a protection task is being executed. After replicas are generated or applications are not unfrozen within the allowed freezing timeout duration, the system automatically runs the unfreezing script to ensure normal service operation.

         Select Enable consistency protection, and then select Application Host (Group) for which the script needs to be executed.

         • If you select System script, perform the following operations:
           1. Select the system script type corresponding to the service host (group).
           2. Set script parameters.
              • On the right of Freezing Script, click Configuring Script Parameters to set parameters for the freezing script. Freezing Script: Freezing Script: this script is used to freeze application I/Os.
              • On the right of Unfreezing Script, click Configuring Script Parameters to set parameters for the unfreezing script. Unfreezing Script: this script is used to unfreeze application I/Os.
              • On the right of Freezing Status Query Script, click Configuring Script Parameters to set parameters for the freezing status query script. Freezing Status Query Script: this script is used to check whether applications are frozen.
              

              • Common parameters are applicable to all scripts. Step parameters are applicable only to the current script.
              • Parameter names and values in the scripts cannot contain special characters. Otherwise, executing the scripts may fail.

                Special characters include ~!@#$%*-_=+[{}];:\,./?.

           3. On the right of Freezing Status Query Script, click Configuring Script Parameters to set parameters for the freezing status query script. Freezing Status Query Script: this script is used to check whether applications are frozen.
         • If you select Customized script, perform the following operations:
           1. Choose Unfreezing Script, Freezing ScriptFreezing Status Query Script, and configure script parameters.
              

              • A self-defined script is not provided by eReplication, so the script provider must ensure the script correctness. Before configuring the script, ensure that the script has been verified.
              • Parameter names and values in the scripts cannot contain special characters. Otherwise, executing the scripts may fail.

                Special characters include ~!@#$%*-_=+[{}];:\,./?.

              • On the right of Freezing Script, click Configuring Script Parameters to set parameters for the freezing script. Freezing Script: Freezing Script: this script is used to freeze application I/Os.
              • On the right of Unfreezing Script, click Configuring Script Parameters to set parameters for the unfreezing script. Unfreezing Script: this script is used to unfreeze application I/Os.
              • On the right of Freezing Status Query Script, click Configuring Script Parameters to set parameters for the freezing status query script. Freezing Status Query Script: this script is used to check whether applications are frozen.
           2. Freezing Timeout indicates the maximum freezing duration supported by host services. The default value is 60 seconds.
      5. Click OK.
         • When System script is selected, In the Warning dialog box that is displayed, read the content of the dialog box carefully and select I have read and understood the consequences associated with performing this operation.. Click OK.
         • When Customized script is selected, the system will automatically deliver commands.

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. Optional: 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 in 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.