Taking snapshots for disaster recovery

In the file system-based IAS disaster recovery solution, there are two ways to create recovery points. They are either scheduled automatically at a regular interval that is defined during the initial setup, or they can be created manually by the user through command line.

Before you begin

Recovery point at the secondary system establishes the recovery point objective (RPO) of the DR solution. It’s the time value after which any data that is modified on the primary system wouldn’t be recovered on secondary system in the event of a primary system disaster. Recovery points are created by the DR solution by periodically marking a recovery point at the primary system and replicating that point to the secondary system. The marking of a recovery point in the primary system is called a snapshot job. By default, the snapshot interval is set to 24 hours. Depending on your business need, you can change the interval value as part of the setup command.

Note: When a snapshot job is running, the database on the primary system is paused for any WRITE operations, for all the applications connected to it. When the snapshot job completes, all the applications are resumed for WRITES.
  • Managing ad hoc snapshot job

    1. To submit an ad hoc snapshot job at any time on the primary system, run the following command:

      apdr sync --run
      Example output: 
      [root@node0101 ~]# apdr sync --run
Generating a new snapshot at primary
Getting APDR status
Successfully submitted a snapshot job at Primary
The id of the snapshot job is: 0
You can use 'apdr sync --status 0' to see the status of this job

    2. Use the job ID provided in the command output to monitor the job status with the:

      apdr sync --status 0
      command. Sample usage:
      [root@node0101 ~]# apdr sync --status 0
Checking status of snapshot job 0. 
Could not get the status of the job. 
Message:  Error: job 0 inqueue. 
      While the snapshot job is completing, the output of the apdr sync --status command contains the following message: 
      Checking status of snapshot job 0. 
Snapshot Job 2 succeded. 
  • Managing scheduled snapshot job

    1. To check the time of the next scheduled snapshot, use

      apdr scheduler status
      command. Example output: 
      [apuser@node0101 ~]$ apdr scheduler status
Interval: 24 hours  Next Snapshot: 2018-12-04 14:00:00 (EST) Scheduler Status: RUNNING

    2. To start the scheduler, run: 

      [apuser@node0101 ~]$ apdr scheduler start
Started the scheduler. 

    3. Stop the scheduler by using the apdr scheduler stop command: 

      [apuser@node0101 ~]$ apdr scheduler stop
Stopped the scheduler. 

    4. You can also set the interval and start time of the scheduler, by running the following command: 

      apdr scheduler set <interval> <starthour> <startminute>
      [apuser@node0101 ~]$ apdr scheduler set 86400 0 0
Changed scheduler parameters. 
Changed scheduler configuration.