What is SQL Server Error 601 & How to Fix It?

When you work in the SQL Server environment, you are most likely to encounter numerous errors. These errors can further disrupt the operations being carried out in the database. Through this article, we are going to discuss a similar issue. The issue we are referring to is the SQL Error 601.  This SQL error is caused by various reasons, and can further affect the users while working on the database. 

Let’s begin by understanding more about the Error 601. Additionally, we will also talk about the methods we can use to resolve this error. 

What is SQL Server Error 601?

When the SQL Server Database is trying to read a page but fails due to possible page corruption or page unavailability, it raises Error 601. There can be different reasons that may lead to this error in the database. We will try to learn and understand these causes one by one to provide better solutions. 

Reasons Leading to this Error 

Some of the common causes for the SQL Server to throw this error are explained here. Let’s take a look at these reasons.

• Corrupted Pages: When the SQL Server fails to read the pages, one of the major reasons can be due to page corruptions. If the page is somehow damaged or has been corrupted, the server may not be able to read them and will raise the error 601. 
• Due to NOLOCK Hint: The NOLOCK hint generally allows the server to read data even if it is in the process of getting modified. But if the data is moved or changed in between of the read process, it may lead to raising this error. 
• File System Issues: File system issues or disk issues can also make the data unreadable. These issues can also lead to this SQL error.

All these reasons somehow contribute to the occurrence of the SQL Error 601 and can create many more challenges for the users. This error can raise concerts like data loss, application downtime, or service disruptions. So, to resolve this issue to help the users, we will now move to the solutions. 

How to Fix the Error 601 SQL Server?

There are various methods that can be used to resolve this error. We will try to learn and  understand these methods one by one to implement them in the correct manner.  The solutions are as follows.

Method 1: Fix Error by Using Cancel the Query Method 

There are two ways to solve the issue if caused due to the NOLOCK hint. The user can either choose to cancel the query for the time being or they can just kill the ongoing process. There are different commands for both these methods. Let’s start with the first option.

Steps to Cancel the Query Method

1. To cancel the query, click on the cancel button in SSMS. 
2. Next, run the following command to identify the cause that is blocking the query. 

These steps will provide the following output for the user to fix the SQL error 601:

• Session ID
• Blocking Session ID
• Query Start Time
• Request Status
• Command Status
• Query Status

Next, if you want to kill the blocking session , write the following command;

This command is used to kill the Session ID.

Moving on to the next method, let’s try to resolve the issue using the Restore from Backup method. 

Method 2: Restore SQL Database using Backup

To fix the SQL Error 601, a user can try the Restore from Backup method. Let’s take a look at how this method works and how users can implement it. 

1. The first step is to open SSMS and connect it to SQL Server.
2. Next, from the object explorer, select the database that you need to restore. 
3. Then, right click on the database and then go to tasks, then restore and then go to Backup. 
4. Configure the required backup settings, and then click on the OK button. 
5. Next, right click on the destination database and then go to task, then Restore and then on Database. 
6. Select the Device option as the source and then browse the backup file.
7. Configure the Restore options as required and then click on the OK button. 
8. Once the database is restored, test the database to verify. 

By following these steps a user can restore their database from backup files. This is another method that can be used to fix the SQL Error 601. Let’s take a look at the next method to understand how it works and how it will help in resolving the issue. The next solution is to resolve the error using the DBCC command. 

Method 3: Using DBCC CHECKDB Command to Resolve the Error

We can also use the DBCC CHECKDB command to fix the SQL Server error 601. The DBCC CHECKDB command is generally used to detect and repair corruption present in the SQL Database. The steps of using this method are:

1. Open SSMS and connect it to the SQL Server.
2. Use the following command to detect database corruption:
   
   DBCC CHECKDB (DBNAME) WITH NO_INFOMSGS;
   

   This command will help you to detect and analyze the corruption present in the database.

3. Once you know the issue, use the repair options to repair the database. Choose one option from the provided repair options based on the intensity of the error;
   REPAIR_FAST, REPAIR_REBUILD, REPAIR_ALLOW_DATA_LOSS
   And then run the command as follows:
   DBCC CHECKDB (DBNAME, REPAIR_ALLOW_DATA_LOSS)
   

   Here, we are considering a situation with severe corruption in the database.

With the help of this method, you can repair the corrupted database and resolve the SQL Error 601. 

On one hand, where all these methods can help to resolve the SQL error, there are some drawbacks of using these methods as well. Let’s take a look at what these drawbacks are and how they can affect the users. 

Drawbacks of Using the Manual Methods

Along with fixing the issue, the manual methods come with drawbacks that can end up creating further challenges for the users. Some of these drawbacks are mentioned here.

Potential Data Loss: The manual methods may offer the solution to resolve the SQL Error 601, but there is a high risk of data loss during the process. The REPAIR_ALLOW_DATA_LOSS repair option is used in case of severe corruption and repairing the database using this method can result in complete data loss. 

Time-taking methods: As we saw earlier, all the methods require proper time from the user to understand and then implement the solutions. Going for a manual method can be a bad idea if  the user is looking for an instant solution.

Technical Complexity: This is one of the major drawbacks of the manual method. If the user who has encountered the error comes from a non-technical background, they may get stuck with the process. All the methods we have discussed require good technical knowledge to carry out the process correctly. Any mistake in the steps may lead to further corruption or data loss.

So, to recommend to you the best solution, we have researched and found an expert solution that can help you with solving the SQL Error, all while overcoming the drawbacks of the manual methods. Let’s take a look at the expert solution now. 

Method 4: Use Expert Solution to Resolve the SQL Error 601

When the manual methods do not work or may end up creating more challenges while solving the error, we can always choose an expert solution. These solutions are generally tried and tested by the experts. The solution we are recommending is using the SQL Recovery Tool. 

The steps for using this solution are:

1. Install and run the solution.
2. To load the files within the software, click on the Open button. 
3. In the Add file window, choose the Quick Scan Option. Then select the SQL Version you’re using. 
4. Enable the Recover Deleted Files option and click on the OK button.
5. After the scan is complete, preview the files and click on the export option. 
6. Choose the destination as SQL Server database, and then configure the required authentication settings. 
7. Select the required files to be exported. Choose export with Schema and data option and click on the save button to export the files.

These steps are as easy as they seem. The simple and straightforward user-interface of the software allows the user to easily understand and follow the steps. This is how users can easily resolve the error and continue working in the database smoothly.

Conclusion

So far in the article, we have learned about the SQL Error 601 and how it is caused. We also learned the methods that can be used to resolve the issue. Along with the manual methods, we have discussed the factors of these methods that may lead to further challenges. At last, we have recommended an expert solution, in case the other methods don’t work or create some problems.