Error 2542

Severity Level 16

Message Text

Table Corrupt: Extent is linked in more than one chain. Check the following allocation page and extent: alloc pg#=%Id extent#=%Id status=%d

Explanation

DBCC CHECKALLOC checks the doubly-linked list used by SQL Server to associate extents with database objects. With this particular error one of the pointers on the extent# is pointing to another object chain. This error is often associated with errors 2541, 2543 and 1117.

Note If DBCC CHECKDB and DBCC CHECKALLOC show no other errors, the data for this object is recoverable either by performing a bcp out or a select into procedure.

Action

Follow these steps:

1. Note the extent# in the message text. For information about the object ID and the index ID of the object that has the error, see Chapter 24, "Additional Problem-solving Techniques."
2. If the object ID is less than or equal to 100, the error is on a system table. Restore the database from a known clean backup.

   If this error occurs on table data (the index ID=0), restore the database from a clean backup.

3. If this error occurs on an object in the database with an ID greater than 100, contact your support provider and have the output from DBCC PAGE, DBCC CHECKALLOC, DBCC CHECKDB, and the SQL Server error log available for review.