functions/Expand-SqlTLogResponsibly.ps1
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function Expand-SqlTLogResponsibly { #AUTHOR: Cl�udio Silva #DATE: 2015-06-13 #Follow me on twitter @ClaudioESSilva #CHANGES: #DATE: 2016-05-22 #Code simplification: # - replacing too many if/else by switch option. # - create instance of server by calling Connect-SqlServer (dbatools - @cl) # - DynamicParam for databases <# .SYNOPSIS This module will help you to automatically grow your T-Log database file in a responsible way (preventing generation of too many VLFs). .DESCRIPTION As you may already know, having a TLog file with too many VLFs can hurt your database performance in many ways. Example: Too many virtual log files can cause transaction log backups to slow down and can also slow down database recovery, and in extreme cases, even affect insert/update/delete performance. References: http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/ http://blogs.msdn.com/b/saponsqlserver/archive/2012/02/22/too-many-virtual-log-files-vlfs-can-cause-slow-database-recovery.aspx http://www.brentozar.com/blitz/high-virtual-log-file-vlf-count/ ... In order to get rid of this fragmentation we need to growth the file taking the following consideration: - How many VLFs are created when we do a grow or when auto-grows hits Note: In SQL Server 2014 this algorithm has changed (http://www.sqlskills.com/blogs/paul/important-change-vlf-creation-algorithm-sql-server-2014/) Atention: We are growing in MB instead of GB because of known issue prior to SQL 2012: More detail here: http://www.sqlskills.com/BLOGS/PAUL/post/Bug-log-file-growth-broken-for-multiples-of-4GB.aspx and http://connect.microsoft.com/SQLServer/feedback/details/481594/log-growth-not-working-properly-with-specific-growth-sizes-vlfs-also-not-created-appropriately or https://connect.microsoft.com/SQLServer/feedback/details/357502/transaction-log-file-size-will-not-grow-exactly-4gb-when-filegrowth-4gb .NOTES What this script will NOT DO for you: 1. Analyse the actual number of VLFs (use DBCC LOGINFO) 2. T-Log backups (BACKUP LOG <databasename> TO DISK="<path>" or using third-party tools) 3. Truncate your transaction log (DBCC SHRINKFILE (N'<database_log>', TRUNCATEONLY). ************************************************************************************************************* 4. Repeat steps 2 and 3 until you have your T-Log with the desired initial size. Then you may run this script. ************************************************************************************************************* You have to make those analysis and take these actions before run this script otherwise only half of the correct process will be made .LINK Understand related problems: http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/ http://blogs.msdn.com/b/saponsqlserver/archive/2012/02/22/too-many-virtual-log-files-vlfs-can-cause-slow-database-recovery.aspx http://www.brentozar.com/blitz/high-virtual-log-file-vlf-count/ Known BUG before SQL Server 2012 http://www.sqlskills.com/BLOGS/PAUL/post/Bug-log-file-growth-broken-for-multiples-of-4GB.aspx http://connect.microsoft.com/SQLServer/feedback/details/481594/log-growth-not-working-properly-with-specific-growth-sizes-vlfs-also-not-created-appropriately https://connect.microsoft.com/SQLServer/feedback/details/357502/transaction-log-file-size-will-not-grow-exactly-4gb-when-filegrowth-4gb .PARAMETER SqlServer Represents the name/ip of the instance where the database(s) that you want to grow exists .PARAMETER Databases This is the list of databases within Instance that this script will grow their t-log files. You can pass only one or many. Can be input by pipeline. (view examples) .PARAMETER TargetLogSizeMB Represents the target log size that log will grow. Expressed in MB. .PARAMETER IncrementSizeMB Represents the size of each grow will perform. Expressed in MB. If you don't provide this parameter the value will be calculated automatically. Otherwise, the input value will be compared with the suggested for your target size. If it is different will ask which one you would like to assume. .PARAMETER LogFileId If you want to grow a secondary, tertiary, other T-Log file you can mention the log file number (FileId column from DBCC LOGINFO output). When not provided, will do on the first T-Log file. .NOTES Author: Cl�udio Silva (@claudioessilva) Requires: ALTER DATABASE permission Limitations: On SQL Server 2005 cannot validate freespace on drive where log file resides. dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com / claudiosil100@gmail.com) Copyright (C) 2016 Cl�udio Silva This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 50000 This is the simplest example. The increment value will be calculated and will grow the T-Log of 'Test' database on 'Localhost' instance to 50000 MB. .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 10000 -IncrementSizeMB 200 Grows the T-Log of 'Test' database on 'Localhost' instance to 1000MB. The increment value will be asked if want to use the input value or the suggested one (calculated automatically) .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 10000 -LogFileNumber 9 Grows the T-Log with FielId 9 of 'Test' database on 'Localhost' instance to 10000MB. .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases (gc D:\DBs.txt) -TargetLogSizeMB 50000 Grows the T-Log of the databases specified in the file 'D:\DBs.txt' on 'Localhost' instance to 50000MB. .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases @("DB1", "DB2") -TargetLogSizeMB 50000 Grows the T-Log of the databases DB1 and DB2 on 'Localhost' instance to 50000MB. .EXAMPLE Expand-DatabaseTLogFileResponsibly -SqlServer '.' -Databases 'Test' -TargetLogSizeMB 50000 -Verbose Use -Verbose to view in detail all actions performed by this script #> [CmdletBinding(SupportsShouldProcess, ConfirmImpact='Medium')] param( [parameter(Position = 1, Mandatory=$true)] [object]$SqlServer, #Position = 2 -> dynamic param Databases is supposed to go here but it doesn't work. [parameter(Position = 3)] [System.Management.Automation.PSCredential]$SqlCredential, [parameter(Position = 4, Mandatory=$true)] [int] $TargetLogSizeMB, [parameter(Position = 5)] [int] $IncrementSizeMB = -1, [parameter(Position = 6)] [int] $LogFileId = -1 ) DynamicParam { if ($SqlServer) { return Get-ParamSqlDatabases -SqlServer $SqlServer -SqlCredential $SourceSqlCredential } } BEGIN { Write-Verbose "Set ErrorActionPreference to Inquire" $ErrorActionPreference = 'Inquire' #Convert MB to KB (SMO works in KB) Write-Verbose "Convert variables MB to KB (SMO works in KB)" [int]$TargetLogSizeKB = $TargetLogSizeMB*1024 [int]$LogIncrementSize = $incrementSizeMB*1024 [int]$SuggestLogIncrementSize = 0 [bool]$LogByFileID = if($LogFileId -eq -1) { $false } else { $true } #Set base information Write-Verbose "Initialize the instance '$SqlServer'" try { $server = Connect-SqlServer -SqlServer $SqlServer -SqlCredential $SqlCredential -ParameterConnection } catch { return } } PROCESS { try { $databases = $psboundparameters.Databases [datetime]$initialTime = Get-Date #control the iteration number $i = 0; #go through all databases Write-Verbose "Processing...foreach database..." foreach ($db in $Databases) { $i+=1 #set step to reutilize on logging operations [string]$step = "$i/$($Databases.Count)" if ($server.Databases[$db]) { Write-Progress ` -Id 1 ` -Activity "Using database: $db on Instance: '$SqlServer'" ` -PercentComplete ($i / $Databases.Count * 100) ` -Status "Processing - $i of $($Databases.Count)" #Validate which log that file will grow if ($LogByFileID) { $logfile = $server.Databases[$db].LogFiles.ItemById($LogFileId) } else { $logfile = $server.Databases[$db].LogFiles[0] } Write-Verbose "$step - Use log file: $logfile" $CurrSize = $logfile.Size Write-Verbose "$step - Log file current size: $([System.Math]::Round($($CurrSize/1024.0), 2)) MB " [long]$requiredSpace = ($TargetLogSizeKB - $CurrSize) Write-Output $logfile Write-Verbose "Verifying if exists sufficient space ($([System.Math]::Round($($requiredSpace / 1024.0), 2))MB) on the volume to performe this task" #Only available from 2008 R2 towards... maybe validate the version and issue a warning saying "can't verify volume free space" if ($requiredSpace -gt $logfile.VolumeFreeSpace) { Write-Output "There is not enough space on volume to perform this task. `r`n" ` "Available space: $([System.Math]::Round($($logfile.VolumeFreeSpace / 1024.0), 2))MB;`r`n" ` " Required space: $([System.Math]::Round($($requiredSpace / 1024.0), 2))MB;" return } else { # SQL 2005 or lower version. The "VolumeFreeSpace" property is empty if ($logfile.VolumeFreeSpace -eq $null) { $choice = "" while ($choice -notmatch "[y|n]") { $choice = read-host "Cannot validate freespace on drive where log file resides? Do you wish to continue (Y/N)" } if ($choice.ToLower() -eq "n") { Write-Output "You have cancelled the execution" #end script return } } if ($CurrSize -ige $TargetLogSizeKB) { Write-Output "$step - [INFO] The T-Log file '$logfile' size is already equal or greater than target size - No action required" } else { Write-Verbose "$step - [OK] There is sufficient free space to perform this task" # If version greater or equal 2012 if ($server.Version.Major -ge "11") { switch ($TargetLogSizeMB) { {$_ -le 64} {$SuggestLogIncrementSize = 64} {$_ -gt 64 -and $_ -lt 256} {$SuggestLogIncrementSize = 256} {$_ -gt 256 -and $_ -lt 1024} {$SuggestLogIncrementSize = 512} {$_ -gt 1024 -and $_ -lt 4096} {$SuggestLogIncrementSize = 1024} {$_ -gt 4096 -and $_ -lt 8192} {$SuggestLogIncrementSize = 2048} {$_ -gt 8192 -and $_ -lt 16384} {$SuggestLogIncrementSize = 4096} {$_ -ge 16384} {$SuggestLogIncrementSize = 8192} } } else # 2008 R2 or under { switch ($TargetLogSizeMB) { {$_ -le 64} {$SuggestLogIncrementSize = 64} {$_ -gt 64 -and $_ -lt 256} {$SuggestLogIncrementSize = 256} {$_ -gt 256 -and $_ -lt 1024} {$SuggestLogIncrementSize = 512} {$_ -gt 1024 -and $_ -lt 4096} {$SuggestLogIncrementSize = 1024} {$_ -gt 4096 -and $_ -lt 8192} {$SuggestLogIncrementSize = 2048} {$_ -gt 8192 -and $_ -lt 16384} {$SuggestLogIncrementSize = 4000} {$_ -ge 16384} {$SuggestLogIncrementSize = 8000} } if (($IncrementSizeMB % 4096) -eq 0) { Write-Output "Your instance version is below SQL 2012, remember the known BUG mentioned on HELP. `r`nUse Get-Help Expand-SqlTLogFileResponsibly to read help`r`nUse a different value for incremente size`r`n" #TODO: Write-error??? return } } Write-Verbose "Instance $server version: $($server.Version.Major) - Suggested TLog increment size: $($SuggestLogIncrementSize)MB" # SMO use values in KB $SuggestLogIncrementSize = $SuggestLogIncrementSize * 1024 # If default will use $SuggestedLogIncrementSize if ($IncrementSizeMB -eq -1) { $LogIncrementSize = $SuggestLogIncrementSize } else { if ($PSCmdlet.ShouldProcess("Confirm increment value", ` "The input value is $([System.Math]::Round($LogIncrementSize/1024, 0))MB. However the suggested value for increment is $($SuggestLogIncrementSize/1024)MB.`r`n Do you want to use the suggested value of $([System.Math]::Round($SuggestLogIncrementSize/1024, 0))MB insted of $([System.Math]::Round($LogIncrementSize/1024, 0))MB", "Choose increment value:")) { $LogIncrementSize = $SuggestLogIncrementSize } } Write-Output "Chunk size: $($LogIncrementSize/1024)MB" #start grow file Write-Verbose "$step - While current size less than wanted log size" while($CurrSize -lt $TargetLogSizeKB) { Write-Progress ` -Id 2 ` -ParentId 1 ` -Activity "Growing file $logfile on '$db' database" ` -PercentComplete ($CurrSize / $TargetLogSizeKB * 100) ` -Status "Remaining - $([System.Math]::Round($($($TargetLogSizeKB - $CurrSize) / 1024.0), 2)) MB" Write-Verbose "$step - Verifying if the log can grow or if has already the desired space allocated" if(($TargetLogSizeKB - $CurrSize) -lt $LogIncrementSize) { Write-Verbose "$step - Log size is lower than the increment size. Setting current size equals $TargetLogSizeKB" $CurrSize = $TargetLogSizeKB } else { Write-Verbose "$step - Grow the $logfile file in $([System.Math]::Round($($LogIncrementSize / 1024.0), 2)) MB" $CurrSize += $LogIncrementSize } #When -WhatIf Switch, do not run if ($PSCmdlet.ShouldProcess("$step - File will grow to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB", "This action will grow the file $logfile on database $db to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB .`r`nDo you wish to continue?", "Performe grow")) { Write-Verbose "$step - Set size $logfile to $([System.Math]::Round($($CurrSize/1024.0), 2)) MB" $logfile.size = $CurrSize Write-Verbose "$step - Applying changes" $logfile.Alter() Write-Verbose "$step - Changes have been applied" #Will put the info like VolumeFreeSpace up to date $logfile.Refresh() } } Write-Verbose "`r`n$step - [OK] Growth process for logfile '$logfile' on database '$db', has been finished." Write-Verbose "$step - Grow $logfile log file on $db database finished" } } #else space available } else #else verifying existance { Write-Output "Database '$db' not exists on instance '$SqlServer'" } } } catch { Write-Output "Logfile $logfile on database $db not processed. Error: $($_.Exception.Message). Line Number: $($_InvocationInfo.ScriptLineNumber)" } finally { $server.ConnectionContext.Disconnect() } } END { Write-Output "Process finished $((Get-Date) - ($initialTime))" } } |