Suddenly I saw my SQL Server is in suspect/OFF Line mode. That's why I am not able to do any any operation in my db. For this reason I restarted my server (Windows Server 2003) .
But when I get ready I found that some of my data has been lost. I have no any back up of my db.
Is there any way to get back the data that I have lost.
the error log:
Could not redo log record (5108:10151:5), for transaction ID
(0:1552370), on page (1:3679), database '??'
The database may go in suspected/offline mode if the location of datafile and the log file have been misplaced accidentally or intentionally, and so after restart the database is unable to find its datafiles and goes in suspect or offline mode. This can be resolved by bringing the datafile and the log file back to the original path that has been configured for the database. After that, the database can be restored with no loss using the command 'Restore with recovery'. The original path for the datafile and the log file can be found in the error log of the server that contains the database.
Try the solution, hope it will help as it did for me.
In another case, the database may go in suspected/offline mode due to off and restart of the server in middle of a transaction and after the restart the transactions may not be committed or rolled back to a consistent state thus leaving database in an inconsistent state turning it suspected or offline. The solution for this is:
alter database <database name> set emergency dbcc checkdb (repair_allow_data_loss)
As the commnand itself states allow data loss, this command may result in loss of some data from the transaction log and hence we may face a data loss, so it is not recommended for a frequent or unapproved use.
In this case, I suggest you check your log file (LDF). In SQL, this log file records all the INSERT, UPDATE, and DELETE query operations performed on a database.
Suppose you have an LDF file. You can work with Restore and recovery process. I used this process for one of my existing clients & It worked.
https://learn.microsoft.com/en-us/sql/relational-databases/backup-restore/restore-and-recovery-overview-sql-server?view=sql-server-ver16
If you do not have a log file, you can use stellar repair for SQL this process helps me to recover my data many times.
Thanks
Related
I had a SQL Server database on an external HDD. I forgot to detach the DB. I do not need it anymore, but I am unable to delete or take it off line.
When I try to delete or take the DB offline, I get the following error.
Msg 823, Level 24, State 2, Line 7
The operating system returned
error 21(The device is not ready.) to SQL Server during a read at
offset 0x00000000012000 in file 'E:\Kenya Air\Monet - Paulus.mdf'.
Additional messages in the SQL Server error log and system event log
may provide more detail. This is a severe system-level 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.
I have tried to run a DBCC CHECK, but I get the same error.
Try taking the database offline and then online.
Alter database DatabaseName set offline
Then bring it back online after a while
Alter database DatabaseName set online
I would try the system stored procedure sp_detach_db in SQL. From the fine manual:
Dropping a database deletes the database from an instance of SQL Server and deletes the physical disk files used by the database. If
the database or any one of its files is offline when it is dropped,
the disk files are not deleted. These files can be deleted manually by
using Windows Explorer. To remove a database from the current server
without deleting the files from the file system, use
sp_detach_db.
The OS is reporting exactly what you said in your question: In dropping the database, SQL Server attempts to remove the file from a device that no longer exists. Thus the database cannot be "dropped", per definition. But perhaps it can be detached, because that affects only the system's internal definition of the list of available databases.
Do NOT try to set the database offline and back online - this will eventually make things worse.
Stop SQL Server - move the respective database files (data and logfile(s)) to a different location. Start SQL Server again - eventually the DB will indicate (restore pending) - now delete the DB from SQL server. Next attach the database files back to the server and you should be ok - unless the files are physically corrupt. I have seen this problem numerous times - especially on virtualized SQL instances where SQL server is set to autostart and wasn't shut down in a coordinated manner before a system reboot. A momentary connection problem to either the data or log file can cause this problem. In case your system shows this problem more than once set SQL server to start manually.
I had the same problem, even when I wanted to take the database offline, it gave me this error.
But the problem was solved by restarting SQL.
I had stuck with one of our team issue where database drive size was overfilled due to log file which was around 150 GB and there was no hope of making any space on server. So, they had detached the database and then deleted to log file. But, then they were then not able to attach the mdf file. I then tried to rebuild log file but it was too not successful as there was no clean shutdown in database. Has anyone gone through this problem and successfully recovered the database?
sp_attach_single_file_db followed by a DBCC CHECKDB should do the trick. Any uncommitted transactions that might still be in that log file will be lost.
If you have an offline database in your metadata, delete that one first with DROP DATABASE but make sure you have a backup of your MDF file.
Currently my db logs for my production SQL Server 2008 R2 server is growing out of control:
DATA file: D:\Data...\MyDB.mdf = 278859 MB on disk
LOG file: L:\Logs...\MyDB_1.ldf = 394542 MB on disk
The server mentioned above has daily backups scheduled #1am & translog backups every 15 min.
The database is replicated in full recovery model to a subscriber. Replciation is pushed from the node above (publisher). That same db log file on the subscriber is ~< 100 GB on disk.
What I did to try and fix:
Run a full backup of the db (takes 1h:47m)
Run the translog backup job which runs every 15 min. (takes 1m:20s)
Run another full backup of the db
Nothing above has worked so I then attempt to shrink the log files which doesn't work either using DBCC SHRINKFILE. The size doesn't ever change.
Can anyone please tell me what is wrong or what I need to do as a SQL Server DBA to resolve the above issue?
Possible things that may stop you from shrinking the translog file:
Long running transaction is occurring on your database
Your replication distribution agent runs quite frequent
Looking at the size of your translog file size, most likely it was caused by the 2nd possibility.
Your replication distribution agent runs quite frequent
SQL Server log reader agent marks the translog file as being used and prevent them from being shrunk, which is what SQL Server does after the translog file is backed up. If this process happens frequent and long enough, this could prevent your translog file from being shrunk on translog scheduled back up.
Look at this MSDN transactional explaination and how to modify log reader agent.
And a thread in MSDN forum that describe similar problem, there is DBCC query here that helps you identify running transaction that may be blocking the translog file (DBCC OPENTRAN).
Long running transaction is occurring on your database
You can check wheter any long running transaction is happening by using DBCC OPENTRAN and what process is running then decide what to do with it. As soon as the long running transaction is finished you should be able to shrink the log file.
After running sp_who2, I noticed a long running transaction on the log that was growing uncontrollably. I used kill on that SPID and not I'm proceeding to shrink the log file.
You should make blank database with same table and migrate your old database data to blank database from migration script.
for eg:
INSERT INTO customers(cust_id, Name, Address)
SELECT cust_id, Name, Address
FROM olddb.customers
--this script should run in new blank database
You can manually shrink you log file
1.right click your database > task > shrink > file > file type=log
than ok
What would happen if I delete the .ldf file that is in the same folder that my .mdf file?
The LDF file is the transaction log and is required for all SQL server configurations. Depending on the recovery mode, will determine how it is used. However all queries basically get stored here until successfully committed to the database (MDF).
You will not be able to delete it while SQL server service is running. You can detach the database, delete the log file (LDF) and reattach the data file (MDF). However it will just create a new log file. You really should not need to delete it. If it is getting too large you will need to manage it, typically through the backup process.
The database will be marked as suspect on SQL Server restart and inaccessible without some in depth fiddling to recover it.
The LDF is an essential part of the database: you need this file.
You can of course ignore us, and delete it and see for yourself...
As already pointed out, the .LDF file is crucial for the DB and the DB will not be available without one. The .LDF can be deleted only if the DB is offline, or detached or SQL Service is stopped.
Assuming that one of the above 3 scenario was true and you did delete the .LDF file, then the DB would be suspect when SQL server is restarted. If the DB was offline and you try to bring it back online, it will give you an error:
File activation failure. The physical file name "<<filename.ldf>>" may be incorrect.
Msg 945, Level 14, State 2, Line 1
Database '<<DB Name>>' cannot be opened due to inaccessible files or insufficient
memory or disk space. See the SQL Server errorlog for details.
Msg 5069, Level 16, State 1, Line 1
ALTER DATABASE statement failed.
It is quite simple to fix this error, but you will need to delete all the Metadata pertaining to the DB from system files. The easiest way to do that would be to drop the DB. Here is what you will need to do.
Take the DB offline or detach the DB
Make a copy of the .MDF file to your backup directory
Now Drop the DB (You will have to reattach the DB, if you detached, of course)
Copy the .MDF back to the original location
After these steps, run the following:
SP_ATTACH_SINGLE_FILE_DB #dbname='<<DBName>>'
,#physname=N'<<filepath\filename.MDF>>'
This should return you the following:
File activation failure. The physical file name "<<Filepath\filename.ldf>>"
may be incorrect.
New log file '<<Filepath\filename.ldf>>' was created.
That would bring your DB back to an usable state.
The million $$$$ question still remains - why would anyone want to delete the .LDF file???
Raj
The best way to keep the size of .LDF file in check is:
to regularly take transaction log backups at least once a day or
change your recovery model from full to simple ( by default, its full)
My sql server marked one database as suspected , on checking i found my mdf,ldf files are missing, but no errors on chkdsk, what it means some virus ?
Either the files were deleted, or they have been moved and a master database backup restored from before the change in location. In both cases the physical files can only be deleted or moved if the database is offline - either because sql server was shut down or the database was closed.
Either of these things is highly unlikely to have happened accidentally. It's unlikely to be a generic virus or trojan as such would either have to specifically delete the files on startup before SQL Server started (assuming your database starts automatically) or shut down the database then specifically delete the files. Given that chkdsk doesn't report errors either it's unlikely to be a disk issue, so it's a virtual certainty that the cause of the error is deliberate database (mis)management.
I think the most likely option is that a dba has decided that the files should be moved elsewhere - typically this is done for space or performance reasons - for instance if a new drive is added to a machine that is running out of space then the database could be moved to that. For some reason a backup of the master database has subsequently been restored from a point before the move.
My first action would be to do a full scan of the system for all mdf/ldf files and (hopefully) locate them. I'd also do a scan of backups and look for the latest master database backup. You could either then try restoring the last master backup and see if that fixed the issue (i'd back up the current master first of course), and failing that, or directly, reattach the missing files.
If you cannot find the mdf/ldf files then your only option is restore from backup. If you don't have a backup then your database is lost.
http://support.microsoft.com/kb/180500
At startup, SQL Server attempts to obtain an exclusive lock on the device file. If the device is being used by another process (for example, backup software) or if the file is missing, the scenario described above will be encountered. In these cases, there is usually nothing wrong with the devices and database. For the database to recover correctly, the device must be made available, and the database status must be reset.
It means someone deleted the files.
They can not be deleted when in use so it happened:
when SQL Server was shut down
the database was closed (Express version usually)
the database was taken offline
All user dbs will share the same folder (edit) by default (end edit) so this is deliberate
The more exotic options include restoring the master db where the databases/MDF files listed in the restored master db do not exist etc. But I doubt it.
In this situation, you can check the SQL Server logs. Go to Management, Click on SQL Server Logs and click on current and check the message.
In my case, I got this:
Error 17207, severity 16, state 1 (it is related to log file deletion or corruption)
Solution:
Set the database into single user mode:
Alter database dbname set single_user
Now set the database into emergency mode:
Alter database dbname set emergency
Repair missing log file or corrupted log file with data loss.
DBCC CHECKDB ('dbname', REAPIR_ALLOW_DATA_LOSS)
Note: You may loss the data by using this command. It also depends on client's approval.
Now set the db in multi user mode;
alter database dbname set multi_user
In SQL Server suspect database is a mode when user unable to connect with database.
At this time user unable to perform any action and can not do anything like no open no backup and no restore etc.
Possible cause for this problem can be one of the following:
1. Database is corrupted
2. Insufficient memory state.
3. unexpected shutdown etc.
4. OS is unable to find the database file