DB Corruption

Question

DB Corruption

MikeRen

Ten Centuries

Points: 1295
More actions
November 15, 2018 at 2:26 am

#368946

Hello,
One of the teams at my place of work came to me with a problem with one of their SharePoint content databases. The server hosting their SharePoint data was on a virtual cluster and this suffered a failure which resulted in all machines being switched off. When the cluster was recovered two of their SQL 2012 databases were marked as SUSPECT; SP_Usage and SP_Teams_02. Running a DBCC CHECKDB ('<db_name>') WITH ALL_ERRORMSGS, NO_INFOMSGS; showed 9 consistency errors in the SP_Usage db and over 6000 consistency errors in the SP_Teams_02 db. Seeing as how the SP_Usage db is supposed to be a log recording location it was decided to simply run a REPAIR_ALLOW_DATA_LOSS action on it and this enabled it to be brought out of SUSPECT mode. The other was more challenging.
My first action was to get a backup of the SP_Teams_02 database restored to another 'test' machine running SQL 2012. This was a file backup of the mdf and ldf files for the corrupted db from the image of the machine 30 seconds before it went down. I ran a DBCC CHECKDB on it and this strangely also showed nearly the same amount of corrupted records. So I had the previous nights db files restored to the same 'test' SQL instance and checked that, again there were corrupted records. A few more backups were restored going back 6 weeks and all showed the same corruption.
At this point I realised that the team hadn't been routinely checking for corruption and so the records had probably been corrupted for many months and were being backed up in that state. Their bad!
Question 1): Why if the data has been corrupted for so long did it not start showing those corruptions in the SQL Event Log until the machine crashed?
Looking at the results of the CHECKDB I can see that most corruptions are of the form:
SQL Server detected a logical consistency-based I/O error: incorrect checksum (expected: 0x9a7b76c4; actual: 0xb6cf5f78). It occurred during a read of page (1:17168692) in database ID 22 at offset 0x000020bf268000 in file 'E:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\SP_Teams_02.mdf'. Additional messages in the SQL Server error log or system event log may provide more detail. This is a severe error condition that threatens database integrity and must be corrected immediately. Complete a full database consistency check (DBCC CHECKDB). This error can be caused by many factors; for more information, see SQL Server Books Online.
Error: 824, Severity: 24, State: 2.
SQL Server detected a logical consistency-based I/O error: incorrect checksum (expected: 0x9a7b76c4; actual: 0xb6cf5f78). It occurred during a read of page (1:17168692) in database ID 22 at offset 0x000020bf268000 in file 'E:\Program Files\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\SP_Teams_02.mdf'. Additional messages in the SQL Server error log or system event log may provide more detail. This is a severe error condition that threatens database integrity and must be corrected immediately. Complete a full database consistency check (DBCC CHECKDB). This error can be caused by many factors; for more information, see SQL Server Books Online.
Error: 7884, Severity: 20, State: 1. (Params:). The error is printed in terse mode because there was error during formatting. Tracing, ETW, notifications etc are skipped.
Error: 7884, Severity: 20, State: 1. (Params:). The error is printed in terse mode because there was error during formatting. Tracing, ETW, notifications etc are skipped.
Error: 7886, Severity: 20, State: 2.
A read operation on a large object failed while sending data to the client. A common cause for this is if the application is running in READ UNCOMMITTED isolation level. This connection will be terminated.
Error: 7105, Severity: 22, State: 9.
The Database ID 22, Page (1:18009656), slot 0 for LOB data type node does not exist. This is usually caused by transactions that can read uncommitted data on a data page. Run DBCC CHECKTABLE.
Error: 7105, Severity: 22, State: 9.
The SQL Event Logs and Windows Event Logs show many similar events. My understanding of these errors is limited but I believe that:
824 is likely to mean that there is a corruption of the file system as there is plenty of free space on the disk. (see MS support).
7884 is likely the be an issue with the network coms.
7105 is likely to be a corruption within the database (see MS support).
Question 2): Is my understanding about these errors close to the mark or do I need to do more research?
I accept that there will have to be data loss to get this database back into a normal state owing to the fact that all known backups exhibit the same symptoms. I attempted a DBCC CHECKDB (N'SP_Teams_02', REPAIR_ALLOW_DATA_LOSS) WITH ALL_ERRORMSGS, NO_INFOMSGS; on the 'test' SQL instance and this was only able to repair (delete!) some of the corruption.
Question 3): Can I identify which LOBs will be affected from a repair so that I can inform the users which data has been deleted?
Question 4): How can I repair the db so that it no longer generates the error messages?
I'm sure this is connected but the production machine is now regularly crashing (every other day) since the initial incident and I suspect that this is something to do with a resource leak. This is affecting the other 'working' databases.
Question 5): What can I look for to identify why the machine keeps crashing?
I know that there will be many actions to take once the machine is stable again to ensure that such a situation doesn't happen again but any help you can offer to get the machine stable would be greatly appreciated.
Thanks,
Mike

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MikeRen Ten Centuries Points: 1295 More actions · Answer 1

Here are the results of running:
DBCC CHECKDB ('SP_Teams_02_Corrupt') WITH NO_INFOMSGS, ALL_ERRORMSGS;
against the 'test' SQL instance db having already had a REPAIR_ALLOW_DATA_LOSS action run against it.

Msg 8904, Level 16, State 1, Line 1
Extent (1:4304936) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:4304936) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:4304952) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:4304952) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:4303704) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:4303704) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:4304600) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:4304600) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:4304624) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:4304624) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:11772928) in database ID 5 is allocated by more than one allocation object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:11772944) in database ID 5 is allocated by more than one allocation object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:11774320) in database ID 5 is allocated by more than one allocation object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:11778208) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:11778208) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12031312) in database ID 5 is allocated by more than one allocation object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12052912) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12052912) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12052968) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12052968) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12053000) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12053000) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12257552) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12257552) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12258296) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12258296) is allocated to 'GAM' and at least one other object.
Msg 8904, Level 16, State 1, Line 1
Extent (1:12258424) in database ID 5 is allocated by more than one allocation object.
Msg 8913, Level 16, State 1, Line 1
Extent (1:12258424) is allocated to 'GAM' and at least one other object.
CHECKDB found 28 allocation errors and 0 consistency errors not associated with any single object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:4303704) is allocated to 'dbo.Workflow, Workflow_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:4304600) is allocated to 'dbo.Workflow, Workflow_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:4304624) is allocated to 'dbo.Workflow, Workflow_CI' and at least one other object.
CHECKDB found 3 allocation errors and 0 consistency errors in table 'Workflow' (object ID 382624406).
Msg 8913, Level 16, State 3, Line 1
Extent (1:11772928) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:11772944) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:11774320) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:11778208) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12031312) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 4, Line 1
Extent (1:12031312) is allocated to 'dbo.AllDocStreams' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12052912) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12052968) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12053000) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12257552) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12258296) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:12258424) is allocated to 'dbo.AllDocStreams, AllDocStreams_CI' and at least one other object.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281339), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281341), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283465), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283470), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283472), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283474), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283479), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283481), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283488), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283490), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283495), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285081), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285082), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285088), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285091), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285097), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285098), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285114), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285556), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285558), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286307), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286309), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289081), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289082), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292608), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292612), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294992), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294993), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294999), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299624), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299630), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281336), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281337), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283466), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283467), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283468), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283469), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283483), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283484), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283485), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283486), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285084), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285085), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285094), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285095), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285100), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285113), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285116), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285552), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285553), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285554), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285555), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286304), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286305), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286306), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289084), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289085), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292609), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292614), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294995), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294996), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299628), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281338), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281342), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281343), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283475), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283476), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283477), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283478), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283491), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283492), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283493), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283494), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285086), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285087), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285092), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285093), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285102), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285103), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285118), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285119), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286311), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289086), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289087), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292615), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294997), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294998), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299625), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299626), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299627), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4281340), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283464), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283471), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283473), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283480), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283482), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283487), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4283489), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285080), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285083), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285089), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285090), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285096), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285099), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285101), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285112), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285115), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285117), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285557), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4285559), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286308), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4286310), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289080), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4289083), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292610), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292611), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4292613), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4294994), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299629), slot 0, text ID 2102198272 is not referenced.
Msg 8964, Level 16, State 1, Line 1
Table error: Object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data). The off-row data node at page (1:4299631), slot 0, text ID 2102198272 is not referenced.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031312) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031313) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031314) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031315) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031316) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031317) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031318) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
Msg 2533, Level 16, State 1, Line 1
Table error: page (1:12031319) allocated to object ID 661577395, index ID 1, partition ID 72057594236502016, alloc unit ID 72057594044153856 (type LOB data) was not seen. The page may be invalid or may have an incorrect alloc unit ID in its header.
CHECKDB found 12 allocation errors and 128 consistency errors in table 'AllDocStreams' (object ID 661577395).
Msg 8913, Level 16, State 3, Line 1
Extent (1:4304936) is allocated to 'dbo.AllFileFragments, AllFileFragments_PartId_UCI' and at least one other object.
Msg 8913, Level 16, State 3, Line 1
Extent (1:4304952) is allocated to 'dbo.AllFileFragments, AllFileFragments_PartId_UCI' and at least one other object.
Msg 8913, Level 16, State 4, Line 1
Extent (1:11772928) is allocated to 'dbo.AllFileFragments, AllFileFragments_PartId_UCI' and at least one other object.
Msg 8913, Level 16, State 4, Line 1
Extent (1:11772944) is allocated to 'dbo.AllFileFragments, AllFileFragments_PartId_UCI' and at least one other object.
Msg 8913, Level 16, State 4, Line 1
Extent (1:11774320) is allocated to 'dbo.AllFileFragments, AllFileFragments_PartId_UCI' and at least one other object.
CHECKDB found 5 allocation errors and 0 consistency errors in table 'AllFileFragments' (object ID 1166627199).
CHECKDB found 48 allocation errors and 128 consistency errors in database 'SP_Teams_02_Corrupt'.
repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB (SP_Teams_02_Corrupt).

DinoRS SSCrazy Points: 2683 More actions · Answer 2

I'll start with Question 1: Pretty simple, if the data stored in that particular area isn't really used, you won't get a message any sooner. Once you start querying (or attempting to) that data you will see enough events in the eventlog, been there seen that.
Question 2: Close I think, 7884 is a TDS Protocol Error, tracing would be the best way to find the cause for this issue. However I have seen similar messages when running dbcc especially when a DB is in a corrupted state - which then takes more time to run the same checks. I think the duration is part of the trouble SQL Server sees in such a situation but I never had the time to trace during DR times. Feel free to Trace and share findings.

MikeRen Ten Centuries Points: 1295 More actions · Answer 3

DinoRS - Thursday, November 15, 2018 5:55 AM
I'll start with Question 1: Pretty simple, if the data stored in that particular area isn't really used, you won't get a message any sooner. Once you start querying (or attempting to) that data you will see enough events in the eventlog, been there seen that.
Question 2: Close I think, 7884 is a TDS Protocol Error, tracing would be the best way to find the cause for this issue. However I have seen similar messages when running dbcc especially when a DB is in a corrupted state - which then takes more time to run the same checks. I think the duration is part of the trouble SQL Server sees in such a situation but I never had the time to trace during DR times. Feel free to Trace and share findings.

I hear what you're saying about Question 1 but the volume of error messages went from zero prior to the crash to 3-4 per second post the crash. Is it conceivable that the data became that popular in such a short time? I could imagine that it might ramp up over time but not as instantaneous as that.

MikeRen Ten Centuries Points: 1295 More actions · Answer 4

I've attached a copy of the results after running
DBCC CHECKDB ('SP_Teams_02') WITH NO_INFOMSGS, ALL_ERRORMSGS;
against the production server as that shows slightly different results to the 'test' instance.

DinoRS SSCrazy Points: 2683 More actions · Answer 5

just imagine SQL Server expects some other data after the crash to be in that location, afaik once SQL Server knows about corruption he won't stop moaning about it either. Wether you could've noticed this before is partly down to if you do PHYSICAL_ONLY checks during DBCC checks (as they take less time than doing logical checks, too) or not.

MikeRen Ten Centuries Points: 1295 More actions · Answer 6

I typically don't do the PHYSICAL_ONLY checks on my db's - perhaps I should, but in the case reported this is another teams and they don't do checks at all.

muthukkumaran Kaliyamoorthy SSCoach Points: 19026 More actions · Answer 7

The minimum repair is "repair_allow_data_loss" : It looks like a SharePoint database, if it's content database, open a case with MSFT.

repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB (SP_Teams_02_Corrupt).

Check the Gail shaw post -- http://www.sqlservercentral.com/articles/Corruption/65804/

Corruption in the LOB pages

Msg 8964, Level 16, State 1, Line 1
 Table error: Object ID 181575685, index ID 1, partition ID 72057594145669120, alloc unit ID 72057594087800832 (type LOB data). The off-row data node at page (1:2444050), slot 0, text ID 901891555328 is not referenced.

This indicates that there are LOB (large object) pages that are not referenced by any data row. This can come about if there was corruption of the clustered index or heap and the damaged pages were deallocated.

If these are the only errors that CheckDB returns, then running repair with the Allow_Data_Loss will simply deallocate these pages. Since the data rows that the LOB data belongs to does not exist, this will not result in further data loss.

Muthukkumaran Kaliyamoorthy
https://www.sqlserverblogforum.com/

MikeRen Ten Centuries Points: 1295 More actions · Answer 8

Yes, this is a SharePoint content database and not the 8964 errors are not the only ones being reported from a CHECKBD.
Unfortunately I've already tried a DBCC CHECKDB ('SP_Teams_02', REPAIR_ALLOW_DATA_LOSS) WITH NO_INFOMSGS, ALL_ERRORMSGS; on a copy of the corrupt database on my 'test' server and although this repaired many issues it still left me with a few hundred records with it claimed it could not repair.
Is there a way (Hex editor?) which will allow me to manually delete the corrupt pages? This seems a last ditch attempt to recover something but I think I'm nearly at that stage.
My other target for today is to script out the entire database and create it as an empty shell. Then, somehow, export all the data that I can from the corrupt db to the empty shell. I'll try this first on my 'test' server to see if it works.

Question 6): Can I simply use the Import and Export tool to copy data from the corrupt database to the empty shell or do I need to physically extract it into another file format first?

muthukkumaran Kaliyamoorthy SSCoach Points: 19026 More actions · Answer 9

MikeRen - Friday, November 16, 2018 12:53 AM
Yes, this is a SharePoint content database and not the 8964 errors are not the only ones being reported from a CHECKBD.
Unfortunately I've already tried a DBCC CHECKDB ('SP_Teams_02', REPAIR_ALLOW_DATA_LOSS) WITH NO_INFOMSGS, ALL_ERRORMSGS; on a copy of the corrupt database on my 'test' server and although this repaired many issues it still left me with a few hundred records with it claimed it could not repair.
Is there a way (Hex editor?) which will allow me to manually delete the corrupt pages? This seems a last ditch attempt to recover something but I think I'm nearly at that stage.
My other target for today is to script out the entire database and create it as an empty shell. Then, somehow, export all the data that I can from the corrupt db to the empty shell. I'll try this first on my 'test' server to see if it works.
Question 6): Can I simply use the Import and Export tool to copy data from the corrupt database to the empty shell or do I need to physically extract it into another file format first?

I had kinda same issue, even we had a corrupted backup.
We restored a month old backup and repaired the corrupted database and the repair had a minimum loss and we used that and fetch missing documents from the corrupted database from frame. It's still running on more than two years 🙂

Reg question, you can try both if you have a timeline and choose the good one.

Muthukkumaran Kaliyamoorthy
https://www.sqlserverblogforum.com/

Johnson Welch SSCoach Points: 18773 More actions · Answer 10

The cause of getting SQL error 824 are many. Hardware issue, Corrupt or damaged MDF/NDF file or any discrepancies in SQL file system are some of the reason of getting SQL Server error 824. This blog may help you out:
https://www.sqlserverlogexplorer.com/sql-error-824/

MikeRen Ten Centuries Points: 1295 More actions · Answer 11

It's been a while since I last updated this thread and have to report that I was unsuccessful in recovering the corrupt database. The team responsible for it eventually ported what they could to another instance and requested content owners to recreate what they needed to.

What I've learnt through this process is that regular checking of the integrity of both the physical infrastructure and the logical data would have reduced the impact of this failure. I shall be recommending to all DB teams at my work that scheduled maintenance tasks are created and monitored from now on.