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Errors on dbcc checkdb

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Topic

pjavan
Starting Member

1 Post

Posted - 2007-10-12 : 16:25:55

I've seen a lot of approaches to this, but I wanted to check here first before trying anything. Unfortunately, I just arrived and looking over the database, realized their backups have been failing for quite sometime. The application using the database is running fine so far, but backing it up freezes. I run DBCC CHECKDB (MyDB) WITH NO_INFOMSGS, ALL_ERRORMSGS and get:

Msg 8909, Level 16, State 1, Line 1
Table error: Object ID 0, index ID -1, partition ID 0, alloc unit ID 844424953200640 (type Unknown), page ID (1:26483) contains an incorrect page ID in its page header. The PageId in the page header = (0:0).
Msg 8909, Level 16, State 1, Line 1
Table error: Object ID 0, index ID -1, partition ID 0, alloc unit ID 2533274801405952 (type Unknown), page ID (1:24589) contains an incorrect page ID in its page header. The PageId in the page header = (0:-1694496760).
Msg 8909, Level 16, State 1, Line 1
Table error: Object ID 0, index ID -1, partition ID 0, alloc unit ID 2533274811367424 (type Unknown), page ID (1:24301) contains an incorrect page ID in its page header. The PageId in the page header = (0:-1694496747).
Msg 8909, Level 16, State 1, Line 1
Table error: Object ID 0, index ID -1, partition ID 0, alloc unit ID 2533279088508928 (type Unknown), page ID (1:24334) contains an incorrect page ID in its page header. The PageId in the page header = (0:0).
CHECKDB found 0 allocation errors and 4 consistency errors not associated with any single object.
Msg 8928, Level 16, State 1, Line 1
Object ID 1093578934, index ID 1, partition ID 353143765729280, alloc unit ID 71668789018624 (type In-row data): Page (1:22417) could not be processed. See other errors for details.
Msg 8978, Level 16, State 1, Line 1
Table error: Object ID 1093578934, index ID 1, partition ID 353143765729280, alloc unit ID 71668789018624 (type In-row data). Page (1:521649) is missing a reference from previous page (1:22417). Possible chain linkage problem.
Msg 8939, Level 16, State 98, Line 1
Table error: Object ID 1093578934, index ID 1, partition ID 353143765729280, alloc unit ID 353143765729280 (type In-row data), page (1:22417). Test (IS_OFF (BUF_IOERR, pBUF->bstat)) failed. Values are 29362185 and -1.
Msg 8976, Level 16, State 1, Line 1
Table error: Object ID 1093578934, index ID 1, partition ID 353143765729280, alloc unit ID 353143765729280 (type In-row data). Page (1:22417) was not seen in the scan although its parent (1:479) and previous (1:715544) refer to it. Check any previous errors.
CHECKDB found 0 allocation errors and 4 consistency errors in table 'WebGroups' (object ID 1093578934).
Msg 8929, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 130617058000896 (type In-row data): Errors found in off-row data with ID 1606680576 owned by data record identified by RID = (1:1620895:7)
Msg 8929, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 130617058000896 (type In-row data): Errors found in off-row data with ID 1606811648 owned by data record identified by RID = (1:1620895:8)
Msg 8929, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 130617058000896 (type In-row data): Errors found in off-row data with ID 1607073792 owned by data record identified by RID = (1:1620895:10)
Msg 8929, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 130617058000896 (type In-row data): Errors found in off-row data with ID 1607204864 owned by data record identified by RID = (1:1620895:11)
Msg 8929, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 130617058000896 (type In-row data): Errors found in off-row data with ID 1608908800 owned by data record identified by RID = (1:1620896:10)
Msg 8928, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data): Page (1:24301) could not be processed. See other errors for details.
Msg 8965, Level 16, State 1, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data). The off-row data node at page (1:24301), slot 0, text ID 1606680576 is referenced by page (1:24298), slot 0, but was not seen in the scan.
Msg 8928, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data): Page (1:24334) could not be processed. See other errors for details.
Msg 8965, Level 16, State 1, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data). The off-row data node at page (1:24334), slot 0, text ID 1606811648 is referenced by page (1:24331), slot 0, but was not seen in the scan.
Msg 8928, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data): Page (1:24462) could not be processed. See other errors for details.
Msg 8939, Level 16, State 98, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data), page (1:24462). Test (IS_OFF (BUF_IOERR, pBUF->bstat)) failed. Values are 29362185 and -1.
Msg 8965, Level 16, State 1, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data). The off-row data node at page (1:24462), slot 0, text ID 1607073792 is referenced by page (1:24429), slot 0, but was not seen in the scan.
Msg 8928, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data): Page (1:24589) could not be processed. See other errors for details.
Msg 8965, Level 16, State 1, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data). The off-row data node at page (1:24589), slot 0, text ID 1607204864 is referenced by page (1:24591), slot 0, but was not seen in the scan.
Msg 8928, Level 16, State 1, Line 1
Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data): Page (1:26483) could not be processed. See other errors for details.
Msg 8965, Level 16, State 1, Line 1
Table error: Object ID 1993058136, index ID 1, partition ID 412092034711552, alloc unit ID 71906736119218176 (type LOB data). The off-row data node at page (1:26483), slot 0, text ID 1608908800 is referenced by page (1:26470), slot 0, but was not seen in the scan.
CHECKDB found 0 allocation errors and 16 consistency errors in table 'Docs' (object ID 1993058136).
CHECKDB found 0 allocation errors and 24 consistency errors in database 'MyDB'.
repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB (MyDB).

Kristen
Test

22859 Posts

Posted - 2007-10-12 : 17:08:59

Copy the file [stop SQL Server and copy, don't risk detaching], and a full backup, preferably copy them to another machine where you can have a play.

Assuming there are no backups readily available you will have to start from this.

Immediately stop all use of this database. You have no idea whether data that is entered is actually going to be retrievable.

You could rescue whatever data you can easily, and put that in a fresh database, and then work on rescuing whatever additional data you can, over time, thereafter.

Its a big job, so sacrificing data right now is your best approach in terms of overall time spent.

Are ALL the errors in the 'Docs' table? How critical is that? Will loss of data cause referential integrity errors that will muck up other things by causing collateral damage? (Or will that be a bonus as you will know WHAT is missing?)

If you need convincing [ad I wouldn't blame you!] here is recent thread where the Techie has spent, by my calculation, 3 weeks trying to salvage data:

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=89758

Kristen

paulrandal
Yak with Vast SQL Skills

899 Posts

Posted - 2007-10-12 : 17:26:32

To further what Kristen has said, here's the plain english version of what CHECKDB said. You've got 3 corrupt pages at the leaf level of the clustered index of the Docs table.

Your choices are to salvage the data or run repair, plus do root cause analysis to figure out what went wrong (when its a page ID problem where the page header has been overwritten the issue is the IO subsystem 99.9999% of the time)

Let us know if you need any guidance.

Paul Randal
Managing Director, SQLskills.com

Vish_1x1
Starting Member

5 Posts

Posted - 2009-02-03 : 05:24:19

Please let me know how to repair the corrupt leaf or pages.
I am facing the same problem...

Vish4u

tosscrosby
Aged Yak Warrior

676 Posts

Posted - 2009-02-03 : 09:43:15

A couple of ways, and this would be my first choice, restore from a good backup (if you don't have one, why not??), drop and rebuild the index to see if that clears the issue or, lastly, DBCC CheckDB 'dbname', REPAIR_ALLOW_DATA_LOSS which potentially will lead to some data loss (no way to tell what will be lost).

Terry

-- Procrastinate now!

GilaMonster
Master Smack Fu Yak Hacker

4507 Posts

Posted - 2009-02-03 : 10:40:09

quote:
Originally posted by Vish_1x1

Please let me know how to repair the corrupt leaf or pages.
I am facing the same problem...

Please start a new thread and post the full output of the following.

DBCC CheckDB ('<Database name>') WITH NO_INFOMSGS, ALL_ERRORMSGS

I don't like offering advice on corruption without seeing exactly what's wrong first.

--
Gail Shaw
SQL Server MVP

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