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DAG behaviour if Active DB copy corrupt

    Question

  • Hi all,

    My friend had to work for 3 days and nights when there is data corruption in his Exchange 2013 server without DAG. He had to move all users to new DB in another storage.

    My most of the clients have DAG setup. However, I'm wondering 2 questions:

    1. If there is little corruption in Active DB copy, will it seed to Passive DB copy?

    2. I know if some mailboxes are quarantined in Active DB copy (Eg. Server 1), they will be auto quarantine in all passive DB copies (Eg. Server 2). If I activate Passive DB copy (Eg. Server 2), remove previously active DB copy (Eg. Server 1) and seed again. Will that DB be in good health?

    Thanks a lot!

    Friday, February 9, 2018 1:19 PM

Answers

  • Hi all,

    My friend had to work for 3 days and nights when there is data corruption in his Exchange 2013 server without DAG. He had to move all users to new DB in another storage.

    My most of the clients have DAG setup. However, I'm wondering 2 questions:

    1. If there is little corruption in Active DB copy, will it seed to Passive DB copy?

    2. I know if some mailboxes are quarantined in Active DB copy (Eg. Server 1), they will be auto quarantine in all passive DB copies (Eg. Server 2). If I activate Passive DB copy (Eg. Server 2), remove previously active DB copy (Eg. Server 1) and seed again. Will that DB be in good health?

    Thanks a lot!

    Depends on the nature of the corruption. If hardware or anti virus caused for example, the it wont be replicated.

    If logical corruption, it could be. That's where lagged copies come into play.

    Friday, February 9, 2018 1:21 PM
    Moderator
  • Agree with Andy David

    It depends on type of corruption: Logical and Physical 

    Physical corruption:

    1. It occurs when the database from an ESE structure is no longer valid in some way (e.g. “Dirty Shutdown” due to a hardware failure). Those corruption couldn´t replicate. you couldn´t bring the EDB online. In this case, check following articles:
    https://practical365.com/exchange-server/exchange-server-database-corruption-and-dirty-shutdown-scenarios/
    https://www.stellarinfo.com/article/resolve-exchange-dirty-shutdown-error.php

    Logical corruption:

    2. It occurs when the data within the database is no longer valid, but the structure from an ESE perspective is valid. Those corruption can replicate (but will also occur in a stand alone Exchange server). There are different methods to deal with it:

    You can move the mailbox.
    You can and use single item recovery.
    You can use New-MailboxRepairRequest  

    Wednesday, February 14, 2018 6:47 AM

All replies

  • Hi all,

    My friend had to work for 3 days and nights when there is data corruption in his Exchange 2013 server without DAG. He had to move all users to new DB in another storage.

    My most of the clients have DAG setup. However, I'm wondering 2 questions:

    1. If there is little corruption in Active DB copy, will it seed to Passive DB copy?

    2. I know if some mailboxes are quarantined in Active DB copy (Eg. Server 1), they will be auto quarantine in all passive DB copies (Eg. Server 2). If I activate Passive DB copy (Eg. Server 2), remove previously active DB copy (Eg. Server 1) and seed again. Will that DB be in good health?

    Thanks a lot!

    Depends on the nature of the corruption. If hardware or anti virus caused for example, the it wont be replicated.

    If logical corruption, it could be. That's where lagged copies come into play.

    Friday, February 9, 2018 1:21 PM
    Moderator
  • Agree with Andy David

    It depends on type of corruption: Logical and Physical 

    Physical corruption:

    1. It occurs when the database from an ESE structure is no longer valid in some way (e.g. “Dirty Shutdown” due to a hardware failure). Those corruption couldn´t replicate. you couldn´t bring the EDB online. In this case, check following articles:
    https://practical365.com/exchange-server/exchange-server-database-corruption-and-dirty-shutdown-scenarios/
    https://www.stellarinfo.com/article/resolve-exchange-dirty-shutdown-error.php

    Logical corruption:

    2. It occurs when the data within the database is no longer valid, but the structure from an ESE perspective is valid. Those corruption can replicate (but will also occur in a stand alone Exchange server). There are different methods to deal with it:

    You can move the mailbox.
    You can and use single item recovery.
    You can use New-MailboxRepairRequest  

    Wednesday, February 14, 2018 6:47 AM