functions/Test-DbaMaxMemory.ps1
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#ValidationTags#Messaging,FlowControl,Pipeline,CodeStyle# function Test-DbaMaxMemory { <# .SYNOPSIS Calculates the recommended value for SQL Server 'Max Server Memory' configuration setting. Works on SQL Server 2000-2014. .DESCRIPTION Inspired by Jonathan Kehayias's post about SQL Server Max memory (http://bit.ly/sqlmemcalc), this script displays a SQL Server's: total memory, currently configured SQL max memory, and the calculated recommendation. Jonathan notes that the formula used provides a *general recommendation* that doesn't account for everything that may be going on in your specific environment. .PARAMETER SqlInstance The target SQL Server instance or instances. .PARAMETER SqlCredential Windows or Sql Login Credential with permission to log into the SQL instance .PARAMETER Credential Windows Credential with permission to log on to the server running the SQL instance .PARAMETER EnableException By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message. This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting. Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch. .NOTES Tags: MaxMemory, Memory Author: Chrissy LeMaire (@cl), netnerds.net Website: https://dbatools.io Copyright: (c) 2018 by dbatools, licensed under MIT License: MIT https://opensource.org/licenses/MIT .LINK https://dbatools.io/Test-DbaMaxMemory .EXAMPLE PS C:\> Test-DbaMaxMemory -SqlInstance sqlcluster,sqlserver2012 Calculate the 'Max Server Memory' settings for all servers within the SQL Server Central Management Server "sqlcluster" .EXAMPLE PS C:\> Test-DbaMaxMemory -SqlInstance sqlcluster | Where-Object { $_.SqlMaxMB -gt $_.TotalMB } | Set-DbaMaxMemory Find all servers in CMS that have Max SQL memory set to higher than the total memory of the server (think 2147483647) and set it to recommended value. #> [CmdletBinding()] param ( [parameter(Position = 0, Mandatory, ValueFromPipeline)] [Alias("ServerInstance", "SqlServer", "SqlServers")] [DbaInstanceParameter[]]$SqlInstance, [PSCredential]$SqlCredential, [PSCredential]$Credential, [Alias('Silent')] [switch]$EnableException ) process { foreach ($instance in $SqlInstance) { Write-Message -Level VeryVerbose -Message "Processing $instance" -Target $instance try { $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential } catch { Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue } Write-Message -Level Verbose -Target $instance -Message "Retrieving maximum memory statistics from $instance" $serverMemory = Get-DbaMaxMemory -SqlInstance $server try { Write-Message -Level Verbose -Target $instance -Message "Retrieving number of instances from $($instance.ComputerName)" if ($Credential) { $serverService = Get-DbaService -ComputerName $instance -Credential $Credential -EnableException } else { $serverService = Get-DbaService -ComputerName $instance -EnableException } $instanceCount = ($serverService | Where-Object State -Like Running | Where-Object InstanceName | Group-Object InstanceName | Measure-Object Count).Count } catch { Write-Message -Level Warning -Message "Couldn't get accurate SQL Server instance count on $instance. Defaulting to 1." -Target $instance -ErrorRecord $_ $instanceCount = 1 } if ($null -eq $serverMemory) { continue } $reserve = 1 $maxMemory = $serverMemory.SqlMaxMB $totalMemory = $serverMemory.TotalMB if ($totalMemory -ge 4096) { $currentCount = $totalMemory while ($currentCount / 4096 -gt 0) { if ($currentCount -gt 16384) { $reserve += 1 $currentCount += -8192 } else { $reserve += 1 $currentCount += -4096 } } $recommendedMax = [int]($totalMemory - ($reserve * 1024)) } else { $recommendedMax = $totalMemory * .5 } $recommendedMax = $recommendedMax / $instanceCount [pscustomobject]@{ ComputerName = $server.ComputerName InstanceName = $server.ServiceName SqlInstance = $server.DomainInstanceName InstanceCount = $instanceCount TotalMB = [int]$totalMemory SqlMaxMB = [int]$maxMemory RecommendedMB = [int]$recommendedMax } | Select-DefaultView -Property ComputerName, InstanceName, SqlInstance, InstanceCount, TotalMB, SqlMaxMB, RecommendedMB } } } |