The transaction log of first storage group in Exchange Server is E00.log, which is renamed and then closed with a consecutive number once it gets full. Since this is the only file that is active and being written to, it can easily get 'torn writes'. A 'torn write' is basically an uncommitted write that is remained in this file after Exchange Information Store service stops unexpectedly. When Exchange user runs Eseutil to check the consistency of log files, it detects corruption because torn writes bring checksum errors to these files. Exchange Server can fix the torn write problem at the next restart of Exchange database, but not when log files corruption is the consequence of some other factors other than torn writes. Thus database corruption is not corrected and it needs manual exchange server recovery solutions.
To discuss such events further, let's take a related example in Exchange Server 2003 or Exchange Server 2000. An Exchange Server computer undergoes a power failure. After this, when the administrator tries to start the Exchange database, it fails and encounters an Event ID 465 logging in the application log. The description section is read as below:
“Information Store (2428) Corruption was detected during soft recovery in log file E:\exchsrvr\THIRD\E00123ab.log. The failing checksum record is located at position 8189:328. Data not matching the log-file fill pattern first appeared in sector 8195.”
This error describes that database corruption cannot be repaired by Exchange Server.
As the error mentions, E00123ab.log file is corrupted. A log file that has been renamed and closed cannot be repaired by Exchange Server. The above event occurs because Exchange discards such data and doesn't replay it.
Following are the basic solutions to solve these problems:
Check for a backup of damaged log file ( E00123ab.log file for this case)
Reject all the log files that are newer to the mentioned log file and then restore the database from last available backup
Backup the database files and perform exchange server recovery by using Eseutil /p hard repair utility
Use a third-party exchange recovery software to run safe and effective database repair
Stellar Phoenix Mailbox Exchange Recovery is a professional tool that repairs corrupted Exchange database and restores individual mailboxes as *.pst files. This exchange server recovery software supports MS Exchange Server 2007, 2003, 2000, and 5.5. The tool executes safe scanning procedure and also recovers deleted mailboxes.