Attempt to fetch logical page (1:192479) in database 7 failed. It belongs to allocation unit 72057594061062144 not to 72057594059685888

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Attempt to fetch logical page (1:192479) in database 7 failed. It belongs to allocation unit 72057594061062144 not to 72057594059685888

Surendra Adhikari 211

while selecting from a table, following error has occured. Attempt to fetch logical page (1:192479) in database 7 failed. It belongs to allocation unit 72057594061062144 not to 72057594059685888

Anonymous

2023-04-17T06:12:40.58+00:00

Hi @Surendra Adhikari You can take a look at the answers below. If there is an answer that helps you, please accept it.
Anonymous

2023-04-21T08:40:01.7633333+00:00

Hi @Surendra Adhikari We have not received a response from you. Did the reply could help you? If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. By doing so, it will benefit all community members who are having this similar issue. Your contribution is highly appreciated.

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Anonymous

2023-04-17T06:12:40.58+00:00

Hi @Surendra Adhikari You can take a look at the answers below. If there is an answer that helps you, please accept it.
Anonymous

2023-04-21T08:40:01.7633333+00:00

Hi @Surendra Adhikari We have not received a response from you. Did the reply could help you? If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. By doing so, it will benefit all community members who are having this similar issue. Your contribution is highly appreciated.

Answer 1

Erland Sommarskog 121.9K MVP Volunteer Moderator

This means that your database is corrupt. You can run DBCC CHECKDB to get an idea of how bad the situation is. DBCC will also tell you which repair option that is needed to get rid of the corruption. In many cases, it will say that REPAIR_ALLOW_DATA_LOSS is needed.

If that is so, you should first take a full backup of the database in its current state. You may or may not need it later. Next, you should instead restore a clean backup. Note that if you restore a backup from yesterday, you should run DBCC on this backup as well, as the corruption may have been lingering for a while. You may have to back a couple of days and restore full backups + log backups to get a corruption free database.

Note that this sort of corruption does not happen out of the blue, but it is almost always the case of malfunctioning hardware, most often the I/O subsystem. Unless there have been recent incident like a power failure, you should consider hardware tainted and try to move to a new platform as soon as possible.

I should add the discussion above assumes that you have a critical production database. If this is only personal development database, you may be less strict in the recovery procedure.

Surendra Adhikari 211 Reputation points

2023-04-16T13:27:27.1733333+00:00

Hi Erland, in summary your answer suggests that a backup without corruption is required to be restored. but in blogs, there are steps suggested which could recover the corrupted pages. Are there such steps which we can follow to recover or just ignore them and go on with the backup?
Erland Sommarskog 121.9K Reputation points MVP Volunteer Moderator

2023-04-16T16:05:06.2033333+00:00

As long as you can do it with a repair option to DBCC that is not REPAIR ALLOW_DATA_LOSS, you are fine.

And, yes, it may be possible to save the show by editing pages in a hex editor, but requires intimate knowledge of the storage format. It's certainly something for experts. I've never tried it myself, and I would only do it as a last resort. As I understand it, it's also a time-consuming.

Another alternative is to use BCP or some other tool to extract as miuch as data as possible. If nothing else, this will give you a better idea of how wide-spread the corruption is. That is, you will not be able to extract all rows from corrupted tables. Again, this is something that requires good understanding of what you are doing.

Restoring a clean backup and replaying logs is a much safer way to do.

Answer 2

This error message indicates that SQL Server is unable to fetch a logical page from the database because it belongs to an incorrect allocation unit. Here are some steps you can take to troubleshoot this issue:

Check the database consistency: Run the DBCC CHECKDB command to check the consistency of the database. This command will identify any errors or inconsistencies in the database and provide recommendations for fixing them.
Check the allocation units: Use the DBCC IND command to check the allocation units for the database. This command will provide information about the allocation units and their corresponding pages.
Check the disk space: Ensure that there is enough disk space available for the database. If the disk is full, SQL Server may not be able to allocate new pages for the database.
Restore from backup: If the above steps do not resolve the issue, restore the database from a backup. This will replace the corrupted database with a clean copy from a previous point in time.

Answer 3

RahulRandive 10,486 Volunteer Moderator

Hi Please find the information and possible solution of the error in below Microsoft document. https://learn.microsoft.com/en-US/sql/relational-databases/errors-events/mssqlserver-605-database-engine-error?view=sql-server-ver15 Thank you!

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Attempt to fetch logical page (1:192479) in database 7 failed. It belongs to allocation unit 72057594061062144 not to 72057594059685888

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