Exchange Database is the platform for Exchange Server. Users on MS Exchange have their files stored on Exchange Database and if it becomes corrupt then they are unable to communicate via mail. So, inorder to repair Exchange database it is necessary to understand its system, Exchange database files and log files.
What are Exchange Database log files
The log files are the files that keep each and every record of activity performed on database. To make it simple understand it in terms of banking transactions. Like when we online make a payment the bank generates a transaction ID, with this unique ID the bank can know each and every detail of payment made in same manner the log files work.
The Exchange log files keeps record of each activity on database like insertion/ deletion/ update/ on a database table and query run by users. By Exchange log files user can know the action which caused database corruption and roll back this command to repair database.
Consistent and Inconsistent Database
The relation of clean shutdown and dirty shutdown is directly related to consistent and inconsistent database
Clean Shutdown: If the action in transaction log files get completed and database shutdown properly then database is said to be consistent. After completing the action the log files get detached from database and goes to clean shutdown.
Dirty Shutdown: When the action in log file does not complete with database and it gets shutdown the database goes to inconsistent state. Here the log files does not get detached from database and it said to be as Dirty Shutdown. Dirty shutdown generally occurs whenever there is power failure or wire connectivity issues.
Repair Database with Eseutil and Isinteg command
First check the status of database using eseutil/mh command. Run the command by launching eseutil.exe tool.
Now run the command eseutil/r to perform soft recivery on database. if there are minor errors then they will be removed
If the database is severly damaged then use eseutil/p command for hard recovery and repair database.
This will solve the problem. Else you could try Exchange Database repair tool. This repairs the database efficiently without any data loss.