Archive for October, 2009

What it is and how it works.
Log shipping is the process of transferring transaction logs from one server to another – shipping them. It is used as a form of disaster recovery for a database. It does not have any automated fail over – transfer to the new database will involve human intervention.

Two servers are involved, the Primary server and the Secondary Server. The Primary server is the server with the database that is being protected. The secondary server holds the backup copy of the database.

The database to be protected needs to be in Full or Bulk Logged recovery mode. This is to stop the transaction logs being truncated. A full backup should then be taken and applied to the secondary server. The option No Recovery is used when restoring on the secondary server. This leaves the database in a restoring state. No log shipping is set up and transaction log backups are copied from the primary server to the secondary server and then applied to the restoring database. This has the affect of keeping the database in step with the primary version.

As an extra process login accounts need to be transferred to the secondary server. This way if the database ever has to be brought on line and used access will be the same as it is on the primary server.

How to set up Log Shipping
In this step by step guide I will set up log shipping on the DataImports database from serverA to serverB.

Create a directory on the primary server
On the primary server create a directory for the transaction log backups. The backups will be made into this directory and then copied across to a receiving directory on the secondary server.
I create this under the main maintenance or sql backup directories.
If there is not one there already create a folder called LS. Then create a sub-folder with the name of your database: \\serverA\m$\Backups\LS\dataImports

Create a directory on the secondary server
On the secondary server create a shared directory for receiving the log shipped files.
Again I create this main maintenance or sql backup directories.
If there is not one there already create a folder called LS. Then create a sub-folder with the name of your database: file://serverb/f$/Maint/LS/dataImports

Exclude the database from TLog backups
If you have any maintenance plans which carryout Transaction Log backups for this database you will need to exclude it.

Set recovery model of the database to Full
If the recovery model of the database is simple set it to Full. You can leave it if it is set to Bulk Insert.

Backup the database
Take a full backup of the database in to the folder you created on the primary server and copy it to the new folder on the secondary server.

Create a database on the secondary server and then restore the backup
Create a new database with the same name as the one you are going to log ship.
Now restore the database using the backup you have just taken – make sure you set the file paths to restore over the files you have just created and not try to use the paths the backup sets.
You must select the option to restore with no recovery.

Click OK.

The database name will now have a green arrow next to it and say restoring …
You can also delete the backup file you used for the restore.

Configure Log Shipping
In SSMS right click on the database name and select properties.
Click on Transaction Log Shipping. Now tick the box which says “Enable this as a primary database in a log shipping configuration”
The button ‘Backup Settings’ will now be enabled. Click this and fill out the options.

You should enter the full path to the folder on the primary server. Underneath this you should also enter the local path. In my example the dataimports data rarely changes so I have set different values from the default. I am deleting files older than 24 hours – 72 is the default. I am alerting on 2 hours where 1 is the default. Next click on the schedule button. As the database I am using does not change very often I have scheduled my backups to take place once an hour. The default is every 15 minutes.

Click OK.

You are now on the configuration screen again. There is a white box where it says secondary server instances and databases. Underneath the box click add. Click on the button at the top right which says connect. Enter the secondary server details. The database should be selected by default.

Now you are back on the secondary database settings make sure the option ‘no, the secondary database is initialised’ has been selected. Now click the Copy Files tab. In this screen you need to enter the path for the directory on the secondary server: file://serverb/f$/Maint/LS/dataImports
I change the deleted copied files option to 24 hours again. Now click schedule. I change this to run every hour again – the default is 15 minutes. This time I will also change the start time to 00:15. There is no point it trying to copy the files on the hour as the actual backup is being taken on the hour. Click Ok and that task will be scheduled.

Now click on the Restore Transaction Job task. I change the delay option to 5 minutes and the alert option to 2 hours. This is because I have a slow rate of change and so only copy every hour. Click on schedule again. This time I will set the task to run at 30 minutes past the hour and to run hourly. Click ok and then on the next screen click on again.

You are now on the properties page again.
Click ok again and the server will create the log shipping jobs. Once the two items have gone green you can click close.

Run the Log Shipping Jobs.
On the primary server there will be a job named like LSBackup_DatabaseName.
Run the LSBackup_DatabaseName job and check that a trn backup file has appeared in the folder you created on the primary server.

On the secondary server look for a job like LSCopy_PrimaryServerName_DatabaseName and run this job. You should see the trn file appear in th efoledr you created on ServerB. Now run LSRestore_PrimaryServerName_DatabaseName.

Finally Transfer Logins
You should use SSIS to create a transfer logins task to copy the logins from serverA to serverB. This way if you have to fail the database over to serverB you can enable to logins and won’t have any permissions problems.

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I have used this on most of my servers so that when I click restore or Backup database it doesn’t go off to a directory under programme files on the C drive and goes to the root of the backup directory I use.

SQL 2005 version

This part of the script will display the current default backup directory.
DECLARE @BackupDirectory VARCHAR(100)
EXEC master..xp_regread @rootkey=‘HKEY_LOCAL_MACHINE’,
@key=‘SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\MSSQLServer’,
@value_name=‘BackupDirectory’,
@BackupDirectory=@BackupDirectory OUTPUT
SELECT @BackupDirectory as BackupDirectory
This script will set G:\Maintenance\userData as the new default directory.
EXEC master..xp_regwrite
@rootkey=‘HKEY_LOCAL_MACHINE’,
@key=‘SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\MSSQLServer’,
@value_name=‘BackupDirectory’,
@type=‘REG_SZ’,
@value=‘G:\Maintenance\userData’

SQL 2000 version

DECLARE @BackupDirectory VARCHAR(100)
EXEC master..xp_regread @rootkey=‘HKEY_LOCAL_MACHINE’,
@key=‘SOFTWARE\Microsoft\MsSQLServer\MsSQLServer’,
@value_name=‘BackupDirectory’,
@BackupDirectory=@BackupDirectory OUTPUT
SELECT @BackupDirectory as BackupDirectory
EXEC master..xp_regwrite
@rootkey=‘HKEY_LOCAL_MACHINE’,
@key=‘SOFTWARE\Microsoft\MsSQLServer\MsSQLServer’,
@value_name=‘BackupDirectory’,
@type=‘REG_SZ’,
@value=‘G:\Maintenance\userData’

This script looks at all the Primary Key Indexes in a database and pulls back the name of the column the key is on. It checks where there is a single column key. It then recommends a name for the column of tableNameID – columns which already match this are filtered out.
I have written this because I have a bad habit of naming surrogate Primary Key columns PKID.
In most cases the column which doesn’t match the name formulae it is because it already had a good name – like serverName in my server audit table.

select si.name as IndexName,
so.name as TableName,
sc.name as columnName,
so.name + ‘Id’ as recommendName
from sys.indexes as si
Inner Join sys.objects as so
on si.object_id = so.object_id
Inner Join sys.index_columns as ic
on si.object_id = ic.object_id AND si.index_id = ic.index_id
Inner Join sys.columns as sc
on ic.object_id = sc.object_id and ic.index_column_id = sc.column_id
where si.is_Primary_key = 1
AND 1 = (SELECT count(object_id)
FROM sys.index_columns icInner
WHERE si.object_id = icInner.object_id AND si.index_id = icInner.index_id)
AND so.name + ‘id’ <> sc.name;

Nearly all of this post comes from the blog listeed in the reference below. I have duplicated most of it here as I found it hard to find and I know I am going to come accross this error again.

As well as the notes below the user will also need to be added to the DCOM users group on the server.

When a user tries to connect to SSIS remotely they get an access is denied error. They can connect locally with no problems. Administrators on the remote machine can connect remotely and locally.

For Windows 2003 Server or Windows XP

1. If the user running under non-admin account it needs to be added to Distributed COM Users group
2. Go to Start – Run and type %windir%\system32\Com\comexp.msc to launch Component Services
3. Expend Component Services\Computers\My Computer\DCOM Config
4. Right click on MsDtsServer node and choose properties
5. In MsDtsServer Properties dialog go to Security page
6. Configure your settings as described below step 7
7. Restart SSIS Service

In the Security page we are interested in “Launch and Activation Permissions” section. Click Edit button to see “Launch Permissions” dialog.

“Launch Permissions” dialog allows you to configure SSIS server access per user/group. In the bottom of the dialog you can select:

• Local / Remote Launch permissions if you allow a user/group to start service locally or remotely
• Local / Remote Activation permissions if you allow to a user/group to connect to SSIS server locally or remotely.

Remote Access:
By default low privileged users can only connect to SSIS Server on the local machine when the service already started. It is shown by the fact that only Local Activation checked for Machine\Users group. To grant the user permission connect to the running server remotely you need to check remote activation.

Reference:
http://deepakrangarajan.blogspot.com/2008/03/connecting-to-integration-service-on.html

I separate System database backups and User database backups – although the code is essentially the same.

On Some servers extra databases are added to the not in list – update statistics takes a long time to run on a large database so I will run that separately once a week.

These steps are run nightly.

Each Step is step to progress even if it fails – I don’t want to stop all backups just because one db failed something. I have emails sent to me and I also read the job history log each working day so I pick up these failures.

Step 1: Shrink log file if recovery is simple
This only shrinks the log if the database is in simple recovery mode. You shouldn’t really have to do this but I have had some problems which this cleared up for me.

DECLARE @dbname sysname, @cmd varchar(1000);
DECLARE db_recovery_cursor CURSOR FOR
SELECT [name]
from sys.databases
WHERE [name] not in(‘master’,’tempdb’,’model’,’distribution’,’msdb’)
AND is_read_only = 0
AND recovery_model_desc = ‘Simple’;
OPEN db_recovery_cursor;
FETCH NEXT FROM db_recovery_cursor INTO @dbname;
WHILE @@FETCH_STATUS = 0
BEGIN
DECLARE @databaseId as int;
SELECT @databaseId = database_id
FROM sys.databases
WHERE [name] = @dbname;

DECLARE @LogName as varchar(250);
SELECT @LogName = name
FROM sys.master_files
Where type_Desc = ‘log’
AND database_id = @databaseId;

DECLARE @sql as Varchar(2000);
SET @sql = ‘Use [‘ + @dbName + ‘];’;
SET @sql = @sql + ‘Checkpoint; ‘;
SET @sql = @sql + ‘DBCC ShrinkFile([‘+ @LogName + ‘],30);’;

EXEC(@sql);
FETCH NEXT FROM db_recovery_cursor INTO @dbname;
END;
CLOSE db_recovery_cursor;
DEALLOCATE db_recovery_cursor;

Step 2: Update Usage and Checkpoint and turn off autoshrink
Update usage helps fix problems in space reporting on the database.
Some of our databases were created with auto shrink on – a big no no!

USE Master;
DECLARE @dbName varchar(255);
DECLARE @SQL varchar(255);
DECLARE dbCursor CURSOR Local Fast_Forward FOR
select [name]
From master.sys.databases
WHERE Name not in (‘master’,’msdb’,’tempdb’,’model’,’Distribution’,’Resource’)
And is_read_only = 0
And state_desc = ‘ONLINE’
Order by [name];
OPEN dbCursor;
FETCH NEXT FROM dbCursor INTO @dbName;
WHILE @@FETCH_STATUS = 0
BEGIN
Set @sql = ‘dbcc updateusage ([‘ + @dbName + ‘]) WITH NO_INFOMSGS;’;
Exec (@sql);
Set @sql = ‘Use ‘ + QuoteName(@dbName) + ‘; Checkpoint;’ ;
Exec (@sql);
SET @sql = ‘EXEC sp_dboption ”’ + @dbname + ”’, ”autoshrink”, ”False”;’;
EXEC(@sql);
Use Master;
FETCH NEXT FROM dbCursor INTO @dbName;
END;
CLOSE dbCursor;
DEALLOCATE dbCursor;

Step 3: Integrity Check
Here you may not want to run this against every database every night but if you can you should. I use the Data_purity option as we have a lot of databases that are getting imported from sql 2000

USE Master;
DECLARE @dbName varchar(255);
DECLARE @SQL varchar(255);
DECLARE dbCursor CURSOR Local Fast_Forward FOR
select [name]
From master.sys.databases
WHERE Name not in (‘master’,’msdb’,’tempdb’,’model’,’Distribution’,’Resource’)
And is_read_only = 0
And state_desc = ‘ONLINE’
Order by [name];
OPEN dbCursor;
FETCH NEXT FROM dbCursor INTO @dbName;
WHILE @@FETCH_STATUS = 0
BEGIN
Set @sql = ‘dbcc CHECKDB ([‘ + @dbName + ‘]) WITH NO_INFOMSGS , DATA_PURITY ;’;
Exec (@sql);
FETCH NEXT FROM dbCursor INTO @dbName;
END;
CLOSE dbCursor;
DEALLOCATE dbCursor;

Step 4: Update Stats
Sp_updatestats will only update the stats SQL thinks needs updating. Update statistics will up date stats whether they need it or not. Updating stats will cause stored procs to recompile – which is ok if the stats were out of date but not if they werern’t.

USE Master;
DECLARE @dbName varchar(255);
DECLARE dbCursor CURSOR Local Fast_Forward FOR
select [name] From master.sys.databases
WHERE Name not in (‘master’,’msdb’,’tempdb’,’model’,’Distribution’,’Resource’)
AND is_read_only = 0
AND state_desc = ‘ONLINE’
Order by [name];
OPEN dbCursor;
FETCH NEXT FROM dbCursor INTO @dbName;
WHILE @@FETCH_STATUS = 0
BEGIN
Exec (‘Use [‘ + @dbName + ‘] EXEC SP_updatestats ‘);
FETCH NEXT FROM dbCursor INTO @dbName;
END;
CLOSE dbCursor;
DEALLOCATE dbCursor;

Step 5: Backup and remove old backups
I delete files older than 96 hours – more accurate than x days. On some servers where space is more of a constraint this time is reduced. On out live servers backups are also copied to tape but this process runs outside of sql. Backups will only be removed if there is a corresponding live database. This means if a database is dropped backups will stay on the server until separately dropped – I like having this in case someone wants to restore it. I’ll normally manually delete them after 6 months or so.

If a database is over a certain size I stripe the backup to 4 files.

USE Master;

Declare @delDate as VARCHAR(50);
Set @delDate = CAST(DATEADD(hh, -96, GETDATE()) AS VARCHAR(50));

DECLARE @rootDir as Varchar(255);
SET @rootDir = ‘M:\Backups\User\’; /*Enter path to user backups here*/

DECLARE @dbName varchar(255);
DECLARE @sqlCreateDir varchar(255);

Declare @y as char(4);
Set @y = Cast(Year(getDate()) as char(4));
Declare @m as char(2);
Set @m = Right(‘0’ + Cast(Month(getDate()) as varchar(2)),2);
Declare @d as char(2);
Set @d = Right(‘0’ + Cast(Day(getDate()) as varchar(2)),2);
Declare @date as char(10);
Set @date = @y + ‘_’ + @m + ‘_’ + @d;

Declare @h as char(2);
Set @h = Right(‘0’ + Cast(DatePart(hh,getDate()) as varchar(2)),2);
Declare @mi as char(2);
Set @mi = Right(‘0’ + Cast(DatePart(mi,getDate()) as varchar(2)),2);
Declare @time as char(5);
Set @time = @h + ‘_’ + @mi;

DECLARE dbCursor CURSOR Local Fast_Forward FOR
select [name] From master.sys.databases
WHERE state_desc = ‘ONLINE’
AND Name not in (‘master’,’msdb’,’tempdb’,’model’,’Distribution’,’Resource’)
Order by [name];
OPEN dbCursor;
FETCH NEXT FROM dbCursor INTO @dbName;
WHILE @@FETCH_STATUS = 0
BEGIN
DECLARE @dirPath as varchar(250);
Set @dirPath = @rootDir + @dbName;

Set @sqlCreateDir = ‘master.dbo.xp_create_subdir N”’ + @dirPath + ””;
Exec (@sqlCreateDir);

EXECUTE master.dbo.xp_delete_file 0, @dirPath,N’bak’,@delDate;

DECLARE @size as numeric(25,0);

SELECT @size = b.backup_size
FROM master..sysdatabases d with (nolock)
left join msdb..backupset b with (nolock)
on d.name = b.database_name
AND b.backup_start_date = (select max(backup_start_date)
from msdb..backupset b2
where b.database_name = b2.database_name
and b2.type = ‘D’)
WHERE d.name = @dbName;

Declare @BakName as Varchar(250);
If @size < 2147483648BEGINSet @BakName = @dbName + '_' + @date + '_' + @time + '.bak';–Now run a backup commandDECLARE @BakCommand as varchar(1024);SET @BakCommand = 'BACKUP Database ' + QuoteName(@dbName);SET @BakCommand = @BakCommand + ' TO DISK=''' + @dirPath + '\' + @BakName + '''';SET @BakCommand = @BakCommand + ' WITH INIT, Checksum;';exec (@BakCommand);ENDELSEBEGINSet @BakName = @dbName + '_' + @date + '_' + @time;–Now run a backup commandSET @BakCommand = 'BACKUP Database ' + QuoteName(@dbName);SET @BakCommand = @BakCommand + ' TO DISK=''' + @dirPath + '\' + @BakName + 'a.bak''';SET @BakCommand = @BakCommand + ' ,DISK=''' + @dirPath + '\' + @BakName + 'b.bak''';SET @BakCommand = @BakCommand + ' WITH INIT, Checksum;';exec (@BakCommand);END;FETCH NEXT FROM dbCursor INTO @dbName; END;CLOSE dbCursor; DEALLOCATE dbCursor;

References:
Update Usage: http://msdn.microsoft.com/en-us/library/ms188414.aspx
Check Db with Data_purity: http://www.sqlskills.com/BLOGS/PAUL/post/CHECKDB-From-Every-Angle-How-to-tell-if-data-purity-checks-will-be-run.aspx