Log salvage
When the database server is offline, you can perform a special logical-log backup, called a log salvage. In a log salvage, the database server accesses the log files directly from disk. The log salvage backs up any logical logs that have not yet been backed up and are not corrupted or destroyed.
The log salvage enables you to recover all of your data up to the last available and uncorrupted logical-log file and the last complete transaction.