Exchange Server buffer dependencies are structures that reduce the amount of data to be placed in log files during a B-tree merge or split. When ESE (Extensible Storage Engine) saves data on the Information Store database, recording the changes in the database files is a three-step process. Buffer dependencies may get corrupted, if the links to the data stored in memory buffers are lost due to Exchange computer unexpected shut down during these steps. Owing to this, the Information Store service fails to start and you receive several errors. This type of corruption should be ideally dealt with a backup. But in case, a valid backup is not available, one needs to apply exchange server recovery procedures.
Here is an error that can occur if the above stated issue occurs. Consider an Exchange Server computer that experiences power outage. After this, when Exchange administrator tries to start the Information Store service, it doesn't start and the following error message appears:
This is the decimal error with the corresponding ESE error message as:
Running eseutil /mh command on Information Store database shows that the databases are in dirty shutdown (inconsistent) state.
The buffer dependencies are corrupted.
Use any of the below methods to resolve this:
The best remedy is to restore Information Store from an updated and non-corrupt backup
In case of backup concerns, you should run soft repair for Priv.edb and Pub.edb using eseutil /r command
If soft repair doesn't work, you can force hard repair for the databases. For this, you can run eseutil /p and eseutil /d commands. But it is advisable to backup the databases before running hard repair as this can delete the corrupted pages and bring serious data loss.
Using third-party exchange recovery is however, a better and safe option to extract data from corrupted Exchange databases. The reasons is that these exchange server recovery utilities are designed to run non-destructive algorithms that repair corrupted Exchange databases and finally restore data to a safe location.
Stellar Phoenix Mailbox Exchange Recovery is a comprehensive utility for repairing corrupted Exchange databases and restoring mailboxes in separate *.pst files. The software can restore deleted mailboxes as well and supports Exchange Recovery for databases created in MS Exchange Server 2007, 2003, 2000, and 5.5. The tool can restore *.stm data in an e-mail.