Remove-SQLDatabaseSafely My First Contribution to DBATools

What is DBA Tools?

A collection of modules for SQL Server DBAs. It initially started out as ‘sqlmigration’, but has now grown into a collection of various commands that help automate DBA tasks and encourage best practices.

You can read more about here and it is freely available for download on GitHub I thoroughly recommend that you watch this quick video to see just how easy it is to migrate an entire SQL instance in one command (Longer session here )

Installing it is as easy as

Install-Module dbatools

which will get you over 80 commands . Visit https://dbatools.io/functions/ to find out more information about them

cmdlets

The journey to Remove-SQLDatabaseSafely started with William Durkin b | t who presented to the SQL South West User Group  (You can get his slides here)

Following that session  I wrote a Powershell Script to gather information about the last used date for databases which I blogged about here and then a T-SQL script to take a final backup and create a SQL Agent Job to restore from that back up which I blogged about here The team have used this solution (updated to load the DBA Database and a report instead of using Excel) ever since and it proved invaluable when a read-only database was dropped and could quickly and easily be restored with no fuss.

I was chatting with Chrissy LeMaire who founded DBATools b | t about this process and when she asked for contributions in the SQL Server Community Slack I offered my help and she suggested I write this command. I have learnt so much. I thoroughly enjoyed and highly recommend working on projects collaboratively to improve your skills. It is amazing to work with such incredible professional PowerShell people.

I went back to the basics and thought about what was required and watched one of my favourite videos again. Grant Fritcheys Backup Rant

I decided that the process should be as follows

  1. Performs a DBCC CHECKDB
  2. Database is backed up WITH CHECKSUM
  3. Database is restored with VERIFY ONLY on the source
  4. An Agent Job is created to easily restore from that backup
  5. The database is dropped
  6. The Agent Job restores the database
  7. performs a DBCC CHECKDB and drops the database for a final time

This (hopefully) passes all of Grants checks. This is how I created the command

I check that the SQL Agent is running otherwise we wont be able to run the job. I use a while loop with a timeout like this

$agentservice = Get-Service -ComputerName $ipaddr -Name $serviceName
if ($agentservice.Status -ne 'Running') {
    $agentservice.Start()
    $timeout = new-timespan -seconds 60
    $sw = [diagnostics.stopwatch]::StartNew()
    $agentstatus = (Get-Service -ComputerName $ipaddr -Name $serviceName).Status
    while ($dbStatus -ne 'Running' -and $sw.elapsed -lt $timeout) {
        $dbStatus = (Get-Service -ComputerName $ipaddr -Name $serviceName).Status
    }
}

There are a lot more checks and logic than I will describe here to make sure that the process is as robust as possible. For example, the script can exit after errors are found using DBCC CHECKDB or continue and label the database backup file and restore job appropriately. Unless the force option is used it will exit if the job name already exists. We have tried to think of everything but if something has been missed or you have suggestions let us know (details at end of post)

The only thing I didn’t add was a LARGE RED POP UP SAYING ARE YOU SURE YOU WANT TO DROP THIS DATABASE but I considered it!!

Performs a DBCC CHECKDB

Running DBCC CHECKDB with Powershell is as easy as this

$sourceserver = New-Object Microsoft.SQLServer.Management.Smo.Server "ServerName"
$db = $sourceserver.databases[$dbname]
$null = $db.CheckTables('None')

you can read more on MSDN

Database is backed up WITH CHECKSUM

Stuart Moore is my go to for doing backups and restores with SMO

I ensured that the backup was performed with checksum like this

$backup = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Backup
$backup.Action = [Microsoft.SqlServer.Management.SMO.BackupActionType]::Database
$backup.BackupSetDescription = "Final Full Backup of $dbname Prior to Dropping"
$backup.Database = $dbname
$backup.Checksum = $True

Database is restored with VERIFY ONLY on the source

I used SMO all the way through this command and performed the restore verify only like this

$restoreverify = New-Object 'Microsoft.SqlServer.Management.Smo.Restore'
$restoreverify.Database = $dbname
$restoreverify.Devices.AddDevice($filename, $devicetype)
$result = $restoreverify.SqlVerify($sourceserver)

An Agent Job is created to easily restore from that backup

First I created a category for the Agent Job

Function New-SqlAgentJobCategory {
    param ([string]$categoryname,
        [object]$jobServer)
    if (!$jobServer.JobCategories[$categoryname]) {
        if ($Pscmdlet.ShouldProcess($sourceserver, "Creating Agent Job Category $categoryname")
            {
                try {
                    Write-Output "Creating Agent Job Category $categoryname"
                    $category = New-Object Microsoft.SqlServer.Management.Smo.Agent.JobCategory
                    $category.Parent = $jobServer
                    $category.Name = $categoryname
                    $category.Create()
                    Write-Output "Created Agent Job Category $categoryname"
                }
                catch {
                    Write-Exception $_
                    throw "FAILED : To Create Agent Job Category $categoryname - Aborting"
                }
            }
        }
    }
}

and then generated the TSQL for the restore step by using the script method on the Restore SMO object

This is how to create an Agent Job

$job = New-Object Microsoft.SqlServer.Management.Smo.Agent.Job $jobServer, $jobname
$job.Name = $jobname
$job.OwnerLoginName = $jobowner
$job.Description = "This job will restore the $dbname database using the final backup located at $filename"

and then to add a job step to run the restore command

$jobStep = new-object Microsoft.SqlServer.Management.Smo.Agent.JobStep $job, $jobStepName $jobStep.SubSystem = 'TransactSql' # 'PowerShell' 
$jobStep.DatabaseName = 'master' 
$jobStep.Command = $jobStepCommmand 
$jobStep.OnSuccessAction = 'QuitWithSuccess' 
$jobStep.OnFailAction = 'QuitWithFailure' 
if ($Pscmdlet.ShouldProcess($destination, "Creating Agent JobStep on $destination")
    { 
        $null = $jobStep.Create()
    } 
    $job.ApplyToTargetServer($destination)
    $job.StartStepID = $jobStartStepid 
    $job.Alter()

 

The database is dropped

We try 3 different methods to drop the database

$server.KillDatabase($dbname)
$server.databases[$dbname].Drop()
$null = $server.ConnectionContext.ExecuteNonQuery("DROP DATABASE ")

The Agent Job restores the database

To run the Agent Job I call the start method of the Job SMO Object
    $job = $destserver.JobServer.Jobs[$jobname]
    $job.Start()
    $status = $job.CurrentRunStatus
    while ($status -ne 'Idle') {
        Write-Output " Restore Job for $dbname on $destination is $status"
        $job.Refresh()
        $status = $job.CurrentRunStatus
        Start-Sleep -Seconds 5
    }
Then we drop the database for the final time with the confidence that we have a safe backup and an easy one click method to restore it from that backup (as long as the backup is in the same location)
There are further details on the functions page on dbatools
Some videos of it in action are on YouTube http://dbatools.io/video
You can take a look at the code on GitHub here

You can install it with

Install-Module dbatools
You can provide feedback via the Trello Board or discuss it in the #dbatools channel in the Sqlserver Community Slack
You too can also become a contributor https://dbatools.io/join-us/ Come and write a command to make it easy for DBAs to (this bit is up to your imagination).

Setting Up and Using Azure VM SQL Automated Backup (and Restore)

This weekend I was creating some Azure VMs to test and was required to use the GUI for some screenshots. I have always used my Powershell scripts described here to create my test systems and with a new job taking up a lot of my time had missed the announcement about Azure SQL Automated Backup and Azure SQL Automated Patching so was surprised to see this screen

1

I read the announcement and also the details on MSDN https://msdn.microsoft.com/en-us/library/azure/dn906091.aspx which show that this requires the SQL Server IaaS Agent. This is a default option on new virtual machines.

There are some other considerations too. It is only supported for SQL Server 2014 and Windows Server 2012 and 2012R2 at present and you can set a retention period to a maximum of 30 days but it is automated. You do not have to decide upon the backup strategy Azure will decide the frequency and type of backups dependent upon the workload of the database and some other factors such as

A full backup is taken
○ when an instance is added to use Managed backup
○ When transaction log growth is 1Gb or more
○ At least once a week
○ If the log chain is broken
○ When a database is created

A transaction log backup is taken
– If no log backup is found
– Transaction log space used is 5Mb or larger
– At least once every two hours
– Any time the transaction log backup is lagging behind a full database backup. The goal is to keep the log chain ahead of full backup.

From <https://msdn.microsoft.com/en-gb/library/dn449496(v=sql.120).aspx>

There are some restrictions
– Only database backups are supported
– System databases are not supported so you need to back those up yourself
– You can only back up to Azure storage
– Maximum backup size is 1Tb as this is the maximum size for a blob in Azure storage
– Simple recovery is not supported
– Maximum retention is 30 days – if you are required to keep your backups for longer than 30 days for regulatory or other reasons you could simply use Azure Automation to copy the files to another storage account in Azure)

How to set it up.

If you are using the GUI then you will find SQL Automated Backup in the optional config blade of the set up. You can follow the steps here to set it up. If (like me) you want to use Powershell then use the following code after you have created your Virtual Machine

$storageaccount = "<storageaccountname>"
$storageaccountkey = (Get-AzureStorageKey -StorageAccountName $storageaccount).Primary
$storagecontext = New-AzureStorageContext -StorageAccountName $storageaccount -StorageAccountKey $storageaccountkey

$encryptionpassword = (Get-Credential -message 'Backup Encryption Password' -User 'IGNOREUSER').password
$autobackupconfig = New-AzureVMSqlServerAutoBackupConfig -StorageContext $storagecontext -Enable -RetentionPeriod 10 -EnableEncryption -CertificatePassword $encryptionpassword
Get-AzureVM -ServiceName <vmservicename> -Name <vmname> | Set-AzureVMSqlServerExtension -AutoBackupSettings $autobackupconfig | Update-AzureVM

Once you have run the code, Azure will take care of the rest. Add a couple of databases to your instance and look in the storage account and you will see this

2

3

And in the automaticbackup container you will find the Certificates and master key backups

4

It will also create a credential

5

You can use the same credential to back up your system databases. If like me you use Ola Hallengrens excellent Maintenance Solution then simply change your systems backup job as follows


USE [msdb]
GO
EXEC msdb.dbo.sp_update_jobstep @job_name = 'DatabaseBackup - SYSTEM_DATABASES - FULL', @step_id=1 ,
		@command=N'sqlcmd -E -S $(ESCAPE_SQUOTE(SRVR)) -d master -Q "EXECUTE [dbo].[DatabaseBackup] @Databases = ''SYSTEM_DATABASES'', "https://myaccount.blob.core.windows.net/mycontainer"
		,  @Credential = ''AutoBackup_Credential'', @BackupType = ''FULL'', @Verify = ''Y'', @CleanupTime = NULL, @CheckSum = ''Y'', @LogToTable = ''Y''" -b'
GO

If you need to restore your database then you can use the GUI and when you choose restore you will see this screen

6

Enter your storage account and the key which you can get from the Azure portal. You will notice that the credential has already been selected, click connect and

7

There are all of your backups ready to restore to any point in time that you choose. By clicking script the T-SQL is generated which looks like this


USE [master]
BACKUP LOG [Test] TO  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_LogBackup_2015-07-16_06-21-26.bak'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,
NOFORMAT, NOINIT,  NAME = N'Test_LogBackup_2015-07-16_06-21-26',
NOSKIP, NOREWIND, NOUNLOAD,  NORECOVERY ,  STATS = 5
RESTORE DATABASE [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150714201240+00.bak'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150714202740+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150714224241+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715005741+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715031242+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715052742+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715074243+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715095743+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150715121243+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NORECOVERY,  NOUNLOAD,  STATS = 5
RESTORE LOG [Test] FROM  URL = N'https://sqlbackupstoragebeard.blob.core.windows.net/asqlvm9-mssqlserver/Test_b8bb98d7a235487d9789b3ee8759cf3e_20150716060004+00.log'
WITH  CREDENTIAL = N'AutoBackup_Credential' ,  FILE = 1,  NOUNLOAD,  STATS = 5
GO

There is an important note. Remember this when you have just set it up so that you don’t think that you have done it wrong (which is what I did!)

When you enable Automated Patching for the first time, Azure configures the SQL Server IaaS Agent in the background. During this time, the portal will not show that Automated Patching is configured. Wait several minutes for the agent to be installed, configured. After that the portal will reflect the new settings.

From <https://msdn.microsoft.com/en-us/library/azure/dn961166.aspx>

And also look out for this

8

The password I had chosen was not complex enough but the Powershell script had succeeded and not given me the warning

To set up SQL Automated Patching you follow a similar steps. The setting is again on the OS Config blade and click enable and then you can choose the frequency and duration of the patching.

It is important to remember to choose your maintenance window correctly. If you have set up your SQL VMs correctly you will have them in an availability set and be using either mirroring or Availability Groups and have the VMs set up in the same availability set to ensure availability during the underlying host patching but I had it confirmed by Principal Software Engineering Manager Sethu Srinivasan t via Microsoft PFE Arvind Shyamsundar b | t that the SQL Automated Patching is not HA aware so you will need to ensure that you set the maintenance windows on each VM to ensure that they do not overlap