Forum Discussion

liuyl's avatar
liuyl
Level 6
4 years ago

How to furthest keep the continuity and consistency of HANA log_backup due to its faulty storage

OS environment: SuSE 15SP1
NBU environment: Master/Media/Client 8.2
SAP environment: HANA 2.0 SP04

I wonder whether there is some best pratical way to furthest keep the continuity and consistency of the log_backup when the corresponding storages are unavailable due to some unexpected hard or soft faults. 

Notes: the hard storage might be either a disk array or a tape library.

Linux
  • Nicolai's avatar
    Nicolai
    4 years ago

    Hi liuyl 

    No worries, a restore request is not tied to the current storage unit configuration in a policy

    Let say you have a policy using STU Tape1

    but after some time you change the policy to use Tape2

    Then a restore request show up. Netbackup know in the image catalog where the image is written, and will allocate Tape1 for the restore request. You don't to change the configuration in the policy.

    In a lab environment, try it ou by creating two disk storage units and a storage unit group. Create a test policy and do backup and restore test to see how Netbackup behaves.

    Hope this clarify

  • Nicolai's avatar
    Nicolai
    Moderator
    4 years ago

    Hi liuyl 

    I guess you can do it manual with policies being enabled/disabled depending on what ressource is down. Personally I don't recommend it. Another option is to extend the log file area in SAP Hana so the system can survey if Netbackup environment is down or out for maintenance. 

    What is the problem using a storage unit group ?

    Best Regards
    Nicolai

    • liuyl's avatar
      liuyl
      Level 6
      4 years ago

      Just worry whether the STU groups in its corresponding policy could still find those log_backup images with their own different STUs each other when the log_backup would need to be recovered .

      • Nicolai's avatar
        Nicolai
        Moderator
        4 years ago

        Hi liuyl 

        No worries, a restore request is not tied to the current storage unit configuration in a policy

        Let say you have a policy using STU Tape1

        but after some time you change the policy to use Tape2

        Then a restore request show up. Netbackup know in the image catalog where the image is written, and will allocate Tape1 for the restore request. You don't to change the configuration in the policy.

        In a lab environment, try it ou by creating two disk storage units and a storage unit group. Create a test policy and do backup and restore test to see how Netbackup behaves.

        Hope this clarify

  • liuyl's avatar
    liuyl
    Level 6
    4 years ago

    Would be there other ways for this demand,   except for the STU groups ？

  • Nicolai's avatar
    Nicolai
    Moderator
    4 years ago

    hi liuyl 

    Yes you are correct. A restore will retrieve all required information from the Netbackup catalog. A policy is not required for restore to work. You even delete the policy,  a restore will still work.

    Best Regards
    Nicolai