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Exchange DAG - Transaction Logs RRS feed

  • Question

  • Hi,

    i have some Exchange 2013 DAG running here. Currently, we have 2 Mailbox Servers, each has 4 databases (2 active, 2 passive).

    For Backup consideration, we want to add an additional Mailbox Server which only holds the 4 passive copies and is used for backups (Veeam Backup&Recovery).

    What happens to the transaction Logs on the servers which holds the active copy and are not backuped anymore? Are the Logs also truncated, when they're dropped on the passive server?

    thanks for a hint!

    Friday, October 30, 2015 10:59 AM

Answers

  • Hi,

    i have some Exchange 2013 DAG running here. Currently, we have 2 Mailbox Servers, each has 4 databases (2 active, 2 passive).

    For Backup consideration, we want to add an additional Mailbox Server which only holds the 4 passive copies and is used for backups (Veeam Backup&Recovery).

    What happens to the transaction Logs on the servers which holds the active copy and are not backuped anymore? Are the Logs also truncated, when they're dropped on the passive server?

    thanks for a hint!

    Yes. Backing up the passive copy will truncate logs on all the copies as well - including the active

    Also look at:

    https://technet.microsoft.com/en-us/library/dd335158(v=exchg.150).aspx

    Log truncation works the same in Exchange 2013 as it did in Exchange 2010. Truncation behavior is determined by the replay lag time and truncation lag time settings for the copy.

    The following criteria must be met for a database copy's log file to be truncated when lag settings are left at their default values of 0 (disabled):

    • The log file must have been successfully backed up, or circular logging must be enabled.

    • The log file must be below the checkpoint (the minimum log file required for recovery) for the database.

    • All other lagged copies must have inspected the log file.

    • All other copies (not lagged copies) must have replayed the log file.


    Twitter!: Please Note: My Posts are provided “AS IS” without warranty of any kind, either expressed or implied.

    Friday, October 30, 2015 1:03 PM

All replies

  • Hi,

    i have some Exchange 2013 DAG running here. Currently, we have 2 Mailbox Servers, each has 4 databases (2 active, 2 passive).

    For Backup consideration, we want to add an additional Mailbox Server which only holds the 4 passive copies and is used for backups (Veeam Backup&Recovery).

    What happens to the transaction Logs on the servers which holds the active copy and are not backuped anymore? Are the Logs also truncated, when they're dropped on the passive server?

    thanks for a hint!

    Yes. Backing up the passive copy will truncate logs on all the copies as well - including the active

    Also look at:

    https://technet.microsoft.com/en-us/library/dd335158(v=exchg.150).aspx

    Log truncation works the same in Exchange 2013 as it did in Exchange 2010. Truncation behavior is determined by the replay lag time and truncation lag time settings for the copy.

    The following criteria must be met for a database copy's log file to be truncated when lag settings are left at their default values of 0 (disabled):

    • The log file must have been successfully backed up, or circular logging must be enabled.

    • The log file must be below the checkpoint (the minimum log file required for recovery) for the database.

    • All other lagged copies must have inspected the log file.

    • All other copies (not lagged copies) must have replayed the log file.


    Twitter!: Please Note: My Posts are provided “AS IS” without warranty of any kind, either expressed or implied.

    Friday, October 30, 2015 1:03 PM
  • Hi,

    Does this mean that when configuring the DAG, mailbox database drive and the transaction logs drive can be separated on Exchange 2013?


    /* Server Support Specialist */

    Tuesday, July 4, 2017 12:56 PM
  • https://blogs.technet.microsoft.com/shekhar37k/2014/05/22/moving-database-and-log-file-path-in-exchange-2010-dag-option-1/


    You can change it manually.
    Wednesday, July 5, 2017 1:02 PM
  • https://blogs.technet.microsoft.com/shekhar37k/2014/05/22/moving-database-and-log-file-path-in-exchange-2010-dag-option-1/


    You can change it manually.
    Thanks Aleh :-)

    /* Server Support Specialist */

    Wednesday, July 5, 2017 10:47 PM