Exchange Server public information store database contains all the user mailboxes, apart from the information which is required in Exchange Server environment and thus is considered the most important. However, Information Store also comprises one another database called Public information store database (Public.edb), which manages data in public folders. If a logical crash occurs to the Exchange Server, the database corruption may occur and it will require Exchange Server Repair.
In some of the cases, user may fail to mount the information store database and encounter an event in the application log of Event Viewer:
“Event Type: Error
Event Source: ESE
Event Category: General
Event ID: 505
Description: Information Store (2028) An attempt to open the compressed file “drive:\Exchsrvr\MDBDATA\priv1.edb” for read / write access failed because it could not be converted to a normal file. The open file operation will fail with error -4005 (0xfffff05b). To prevent this error in the future you can manually decompress the file and change the compression state of the containing folder to uncompressed. Writing to this file when it is compressed is not supported. “
Or
“Event Type: Error
Event Source: MSExchangeIS
Event Category: General
Event ID: 9519
Description: Error 0xfffff05b starting database “First Storage Group\Mailbox Store (EXCHANGE)” on the Microsoft Exchange Information Store. Failed to attach to Jet DB.”
This problem is specifically encountered when user upgrades to Exchange Server SP3 or later. It takes place when the information store database has been compressed using NTFS file system compression (Compressed NTFS- generally used to save disk space).
Note: NTFS compression can corrupt Exchange database under critical situations like when the information store reaches to about 4 GB in size, in which Exchange Server Recovery is required.
Exchange Server SP3 and later versions, including Exchange Server 2003 don’t allow NTFS compressed information store to mount. These files are managed by ESE (Extensible Storage Engine) which require sector independence for log-based recovery process, which is not allowed in compressed files. Thus database corruption may result, specifically in database files, larger than 128 MB, which require Exchange Server Repair. Files, smaller than 128 MB, are automatically decompressed in Exchange Server SP3 and later.
In order to resolve the above issue, we need to decompress the folders of Information store databases and logs after dismounting the database. Then, we need to carry out offline defragmentation using ‘eseutil /d’ command and mount the database again. If the database comes out to be corrupt, we need to apply Exchange Server Repair or else perform the online backup of the database.
Exchange Server Recovery can be performed using eseutil utility, but the corrupt pages will be deleted. So, using commercial exchange server repair software can provide complete solutions by utilizing efficient yet safe scanning algorithms to repair the corrupt database.
Stellar Phoenix Mailbox exchange recovery is the finest Exchange Sever Recovery software. It is compatible with Exchange Server 2003, 2000 and 5.5. This Exchange Server Repair software is a user friendly application and has an interactive interface. It recovers mailboxes in PST format, usable with MS Outlook.
