The Microsoft Exchange Server database engine splits a column into several parts when it is found to be too large, and so the long values (LVs) are created. These structures are stored in a different B-Tree (binary tree) of the corresponding table, each with a unique long-value identifier. Each of these LVs has a specific header, called LVROOT, which consists of information such as LV reference count and length. In some cases, this LVROOT can be overwritten (usually due to a faulty B-split operation), ultimately resulting in LV corruption. This can cause Information Store to stop, LV access errors and / or database corruption. To restore the database, you must restore from a suitable backup. If no valid backup is present, then you need to apply an Exchange Repair solution.
To illustrate such problems, suppose you try to perform an offline defragmentation of an Exchange database. But the operation fails with an error like below:
“Operation ended with error -1526 (JET_errLVCorrupted, Corruption found in long value tree) after
Furthermore, when you run the eseutil / g command to check the integrity of the database, the database is reported as damaged.
The above error occurs due to corruption in the LV tree. This can occur in combination with orphan LVs.
You must first check for the backup. If present and valid, restore it. Otherwise, you need to perform the given set of steps to fix this problem:
- Perform eseutil / g with / v and / x parameters for detailed output and investigate for the cause (error, orphaned or damaged)
- If the LVs are damaged, you can run the eseutil / p command. But make sure to back up the database first as it will delete corrupted data
- If the LVs are both damaged and orphaned, run eseutil / d to defragment the database after the repair.
Eseutil / p is a difficult command. So for a safe EDB repair you need to use a third party database recovery program. An Exchange Server Repair Tool uses intensive, but secure scanning algorithms to repair and restore a damaged Exchange database while providing an interactive user interface.
Stellar Phoenix Mailbox Exchange Recovery is an effective solution that recovers and restores a damaged Exchange database to a user-specified location. The safe Repair of Exchange Server solution extracts all user mailboxes as individual.pst files. The tool supports Exchange Server 5.5, 2000 and 2003. It is compatible with Windows 7, Vista, XP, 2003 and 2000.