Here a Microsoft SQL Server issue that disturbs CRM as well:
Large Sizes for reserved size and data size (of sp_spaceused) are reported in SQL for SQL table AsyncOperationBase.
This would mean that row sizes of tables are massive.
It could lead to massive sizes that needs to be released for CRM database on (SAN) disks.
A customer's AsyncOperationBase table grows massively, so the internal stored procedure sp_spaceused AsyncOperationBase is executed in SQL Management Studio. When checking the results, a size of approximately 8.5 MB per row which is far to much, as shown below:
The size is due to ghost records in SQL Server 2008.
Please install the fix (service pack 3) to avoid the issue.