Conditions for Log Truncation in Exchange

These are the conditions in which Exchange's Replication service will truncate the committed log files in Exchange:

Exchange 2010 & 2013
  • 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.
Exchange 2013
Exchange 2013 uses quite a big checkpoint depth (100MB), it’s usual to find a hundred or more transaction logs even when circular logging is enabled and the database is essentially quiescent. It’s far removed from the five or six transaction logs that a standalone database enabled for circular logging might use.