Not getting much into theoretical part, you can read more about features in details from BOL or Search it on the web, let’s start with the issue and resolution.
Issue:
SQL Server shutdown unexpectedly (not clean shutdown) or Server Crashed or disk Crashed. On recovering the system or on starting the SQL Server services Database state changes to suspect. On checking the error you found
Message1:|
FileMgr::StartLogFiles: Operating system error 2(The system cannot find the file specified.) occurred while creating or opening file ‘D:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATADatabase_LogFile.LDF’. Diagnose and correct the operating system error, and retry the operation.
Message2:|
File activation failure. The physical file name “D:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATADatabase_LogFile.LDF” may be incorrect.
Message3:|
The log cannot be rebuilt because there were open transactions/users when the database was shutdown, no checkpoint occurred to the database, or the database was read-only. This error could occur if the transaction log file was manually deleted or lost due to a hardware or environment failure.
Messag4:|
Backup detected log corruption in database system. Context is FirstSector. LogFile: 2 “D:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATADatabase_LogFile.LDF “’ VLF SeqNo: x2572 VLFBase: x4a60000 LogBlockOffset: x4ae3200 SectorStatus: 2 LogBlock.StartLsn.SeqNo: x2043 LogBlock.StartLsn.Blk: x200000 Size: x0 PrevSize: x0
Message5:|
Msg 945, Level 14, State 2, Line 1
Database ‘Database Name’ cannot be opened due to inaccessible files or insufficient memory or disk space. See the SQL Server errorlog for details.
Resolution
In case u lost the Log file (.Ldf)(Disk corruption, file deleted or SQL Server not able access the log file due to latency or disk issue) then the transaction which are not committed or not written to the data pages (hardened) will be lost (Might be possibility that u may see some data consistency issue).
Check the status of the Database by querying the system tables or views
select name,state,state_desc from sys.databases where name=’XYZ’
Name State State_desc Database 3 RECOVERY_PENDING The only possible way to bring the database online is rebuilding the log file.
Set the database in Emergency Mode
ALTER DATABASE XYZ SET EMERGENCY
select name,state,state_desc from sys.databases where name=’XYZ’
Name State State_desc Database 5 EMERGENCY Set the database in single user mode with rollback immediate mode
ALTER DATABASE XYZ SET SINGLE_USER WITH ROLLBACK IMMEDIATE
Rebuild the log file
DBCC CHECKDB(‘XYZ’,REPAIR_ALLOW_DATA_LOSS)
Result MessageFile activation failure. The physical file name “D:Program FilesMicrosoft SQL ServerMSSQL10.MSSQLSERVERMSSQLDATAXYZ_log.LDF” may be incorrect.
The log cannot be rebuilt because there were open transactions/users when the database was shutdown, no checkpoint occurred to the database, or the database was read-only. This error could occur if the transaction log file was manually deleted or lost due to a hardware or environment failure.
Warning: The log for database ‘XYZ’ has been rebuilt. Transactional consistency has been lost. The RESTORE chain was broken, and the server no longer has context on the previous log files, so you will need to know what they were. You should run DBCC CHECKDB to validate physical consistency. The database has been put in dbo-only mode. When you are ready to make the database available for use, you will need to reset database options and delete any extra log files.
Check the database status
select name,state,state_desc from sys.databases where name=’XYZ’
Name State State_desc Database 0 Online The Database is still in single user mode, set it to multi user mode
ALTER DATABASE XYZ SET MULTI_USER
Backup the Database immediately.
good
Amazing, works well, I used this process once 8 months ago, then had the same issue yesterday, found URL in one-Note (glad I took the reference) and used it again, great post, thank you
I have recently noticed that in some cases where storage is SAN,NAS or DAS and the disk reas reponse time is very slow due to HBA card , or Switch link between Storage and Server sql server is not able to read properly and leaves the databases in suspect or in “In Recovery State”. To resolve the issue recycle / bounce the SQL Server Services and if stil database is not recovered engage the Storage and Windows team to investigate the issue.
also I have come across the issue that DB did not recover properly and I could not enter data into the DB