Checksum Error in SQL Server: Checksum function was a new feature introduced in Microsoft SQL Server 2005 to detect errors in the I/O Path. Basically it identifies any corruption or damage of database pages which can take place in I/O path.
Reason for Checksum Error in SQL Server: If your database has checksum function enabled then it performs calculation when you execute a query to backup your database pages. In this case page checksum function starts comparing the value written on the Page Header if it matches then your database is consistent, if it does not matches then you see a Checksum Error in SQL Server environment and start facing the error shown below.
Error: 824, Severity: 24, State: 2. 2010-08-11 06:12:35.51 spid7s SQL Server detected a logical consistency-based I/O error: incorrect checksum (expected: 0x3ee24b20; actual: 0x8d0681bd). It occurred during a read of page (1:375) in database ID 1 at offset 0x000000002ee000 in file 'C: Program FilesMicrosoft SQL Server'
In this situation it is suggested that you check and make sure your disk sub-system and drivers are updated to avert such issues from happening in the future.
SQL Database Disaster Recovery with CHECKDB: It is not advisable to run CHECKDB with REAIR_ALLOW_DATA_LOSS to solve this problem. As you are aware this CHECKDB can also causes the data loss. Usually it drops the pages which are hard to repair. So it not a very good idea to use CHECKDB for SQL Database repair, you might lose some important data tales using this function. And there can be other multiple reasons for database corruption which can not be covered by of SQL Server itself or CHECKDB.
How to Solve Checksum Error in SQL Server? By using the information provided by Checksum you can identify, remove the faulty I/O device which has caused your database corruption. Now if you are seeking MS SQL Database Recovery of your corrupted and damaged database then you can use SysTools SQL Recovery Tool which becomes very useful to restore all your corrupted databases. After you restore corrupted database using SQL Database Repair tool then you should not face Checksum Error again.