functions/Test-DbaDiskAlignment.ps1
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function Test-DbaDiskAlignment { <# .SYNOPSIS Verifies that your non-dynamic disks are aligned according to physical constraints. .DESCRIPTION Returns $true or $false by default for one server. Returns Server name and IsBestPractice for more than one server. Please refer to your storage vendor best practices before following any advice below. By default issues with disk alignment should be resolved by a new installation of Windows Server 2008, Windows Vista, or later operating systems, but verifying disk alignment continues to be recommended as a best practice. While some versions of Windows use different starting alignments, if you are starting anew 1MB is generally the best practice offset for current operating systems (because it ensures that the partition offset % common stripe unit sizes == 0 ) Caveats: * Dynamic drives (or those provisioned via third party software) may or may not have accurate results when polled by any of the built in tools, see your vendor for details. * Windows does not have a reliable way to determine stripe unit Sizes. These values are obtained from vendor disk management software or from your SAN administrator. * System drives in versions previous to Windows Server 2008 cannot be aligned, but it is generally not recommended to place SQL Server databases on system drives. .PARAMETER ComputerName The target computer or computers. .PARAMETER Credential Specifies an alternate Windows account to use when enumerating drives on the server. May require Administrator privileges. To use: $cred = Get-Credential, then pass $cred object to the -Credential parameter. .PARAMETER SQLCredential Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential) .PARAMETER NoSqlCheck If this switch is enabled, the disk(s) will not be checked for SQL Server data or log files. .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: Storage Author: Constantine Kokkinos (@mobileck), https://constantinekokkinos.com Website: https://dbatools.io Copyright: (c) 2018 by dbatools, licensed under MIT License: MIT https://opensource.org/licenses/MIT The preferred way to determine if your disks are aligned (or not) is to calculate: 1. Partition offset - stripe unit size 2. Stripe unit size - File allocation unit size References: - Disk Partition Alignment Best Practices for SQL Server - https://technet.microsoft.com/en-us/library/dd758814(v=sql.100).aspx - Getting Partition Offset information with Powershell - http://sqlblog.com/blogs/jonathan_kehayias/archive/2010/03/01/getting-partition-Offset-information-with-powershell.aspx Thanks to Jonathan Kehayias! - Decree: Set your partition Offset and block Size and make SQL Server faster - http://www.midnightdba.com/Jen/2014/04/decree-set-your-partition-Offset-and-block-Size-make-sql-server-faster/ Thanks to Jen McCown! - Disk Performance Hands On - http://www.kendalvandyke.com/2009/02/disk-performance-hands-on-series-recap.html Thanks to Kendal Van Dyke! - Get WMI Disk Information - http://powershell.com/cs/media/p/7937.aspx Thanks to jbruns2010! .LINK https://dbatools.io/Test-DbaDiskAlignment .EXAMPLE PS C:\> Test-DbaDiskAlignment -ComputerName sqlserver2014a Tests the disk alignment of a single server named sqlserver2014a .EXAMPLE PS C:\> Test-DbaDiskAlignment -ComputerName sqlserver2014a, sqlserver2014b, sqlserver2014c Tests the disk alignment of multiple servers #> param ( [parameter(Mandatory, ValueFromPipeline)] [Alias("ServerInstance", "SqlServer", "SqlInstance")] [DbaInstanceParameter[]]$ComputerName, [System.Management.Automation.PSCredential]$Credential, [System.Management.Automation.PSCredential]$SqlCredential, [switch]$NoSqlCheck, [switch]$EnableException ) begin { Test-DbaDeprecation -DeprecatedOn "1.0.0" -Parameter 'Detailed' $sessionoption = New-CimSessionOption -Protocol DCom function Get-DiskAlignment { [CmdletBinding()] param ( $CimSession, [string]$FunctionName = (Get-PSCallStack)[0].Command, [bool]$NoSqlCheck, [string]$ComputerName, [System.Management.Automation.PSCredential]$SqlCredential, [bool]$EnableException = $EnableException ) $SqlInstances = @() $offsets = @() #region Retrieving partition/disk Information try { Write-Message -Level Verbose -Message "Gathering information about first partition on each disk for $ComputerName." -FunctionName $FunctionName try { $partitions = Get-CimInstance -CimSession $CimSession -ClassName Win32_DiskPartition -Namespace "root\cimv2" -ErrorAction Stop } catch { if ($_.Exception -match "namespace") { Stop-Function -Message "Can't get disk alignment info for $ComputerName. Unsupported operating system." -InnerErrorRecord $_ -Target $ComputerName -FunctionName $FunctionName return } else { Stop-Function -Message "Can't get disk alignment info for $ComputerName. Check logs for more details." -InnerErrorRecord $_ -Target $ComputerName -FunctionName $FunctionName return } } $disks = @() $disks += $($partitions | ForEach-Object { Get-CimInstance -CimSession $CimSession -Query "ASSOCIATORS OF {Win32_DiskPartition.DeviceID=""$($_.DeviceID.Replace("\", "\\"))""} WHERE AssocClass = Win32_LogicalDiskToPartition" | Add-Member -Force -MemberType noteproperty -Name BlockSize -Value $_.BlockSize -PassThru | Add-Member -Force -MemberType noteproperty -Name BootPartition -Value $_.BootPartition -PassThru | Add-Member -Force -MemberType noteproperty -Name DiskIndex -Value $_.DiskIndex -PassThru | Add-Member -Force -MemberType noteproperty -Name Index -Value $_.Index -PassThru | Add-Member -Force -MemberType noteproperty -Name NumberOfBlocks -Value $_.NumberOfBlocks -PassThru | Add-Member -Force -MemberType noteproperty -Name StartingOffset -Value $_.StartingOffset -PassThru | Add-Member -Force -MemberType noteproperty -Name Type -Value $_.Type -PassThru } | Select-Object BlockSize, BootPartition, Description, DiskIndex, Index, Name, NumberOfBlocks, Size, StartingOffset, Type ) Write-Message -Level Verbose -Message "Gathered CIM information." -FunctionName $FunctionName } catch { Stop-Function -Message "Can't connect to CIM on $ComputerName." -FunctionName $FunctionName -InnerErrorRecord $_ return } #endregion Retrieving partition Information #region Retrieving Instances if (-not $NoSqlCheck) { Write-Message -Level Verbose -Message "Checking for SQL Services." -FunctionName $FunctionName $sqlservices = Get-CimInstance -ClassName Win32_Service -CimSession $CimSession | Where-Object DisplayName -like 'SQL Server (*' foreach ($service in $sqlservices) { $instance = $service.DisplayName.Replace('SQL Server (', '') $instance = $instance.TrimEnd(')') $instancename = $instance.Replace("MSSQLSERVER", "Default") Write-Message -Level Verbose -Message "Found instance $instancename" -FunctionName $FunctionName if ($instance -eq 'MSSQLSERVER') { $SqlInstances += $ComputerName } else { $SqlInstances += "$ComputerName\$instance" } } $sqlcount = $SqlInstances.Count Write-Message -Level Verbose -Message "$sqlcount instance(s) found." -FunctionName $FunctionName } #endregion Retrieving Instances #region Offsets foreach ($disk in $disks) { if (!$disk.name.StartsWith("\\")) { $diskname = $disk.Name if ($NoSqlCheck -eq $false) { $sqldisk = $false foreach ($SqlInstance in $SqlInstances) { try { if ($null -ne $SqlCredential) { $smoserver = Connect-SqlInstance -SqlInstance $SqlInstance -SqlCredential $SqlCredential } else { $smoserver = Connect-SqlInstance -SqlInstance $SqlInstance # win auth } $sql = "Select count(*) as Count from sys.master_files where physical_name like '$diskname%'" Write-Message -Level Verbose -Message "Query is: $sql" -FunctionName $FunctionName Write-Message -Level Verbose -Message "SQL Server is: $SqlInstance." -FunctionName $FunctionName $sqlcount = $smoserver.Databases['master'].ExecuteWithResults($sql).Tables[0].Count if ($sqlcount -gt 0) { $sqldisk = $true break } } catch { Stop-Function -Message "Can't connect to $ComputerName ($SqlInstance)." -FunctionName $FunctionName -InnerErrorRecord $_ return } } } if ($NoSqlCheck -eq $false) { if ($sqldisk -eq $true) { $offsets += $disk } } else { $offsets += $disk } } } #endregion Offsets #region Processing results Write-Message -Level Verbose -Message "Checking $($offsets.count) partitions." -FunctionName $FunctionName foreach ($partition in $offsets) { # Unfortunately "Windows does not have a reliable way to determine stripe unit Sizes. These values are obtained from vendor disk management software or from your SAN administrator." # And this is the #1 most impactful issue with disk alignment :D # What we can do is test common stripe unit Sizes against the Offset we have and give advice if the Offset they chose would work in those scenarios $offset = $partition.StartingOffset / 1kb $type = $partition.Type $stripe_units = @(64, 128, 256, 512, 1024) # still wish I had a better way to verify this or someone to pat my back and say its alright. # testing dynamic disks, everyone states that info from dynamic disks is not to be trusted, so throw a warning. Write-Message -Level Verbose -Message "Testing for dynamic disks." -FunctionName $FunctionName if ($type -eq "Logical Disk Manager") { $IsDynamicDisk = $true Write-Message -Level Warning -Message "Disk is dynamic, all Offset calculations should be suspect, please refer to your vendor to determine actual Offset calculations." -FunctionName $FunctionName } else { $IsDynamicDisk = $false } Write-Message -Level Verbose -Message "Checking for best practices offsets." -FunctionName $FunctionName if ($offset -ne 64 -and $offset -ne 128 -and $offset -ne 256 -and $offset -ne 512 -and $offset -ne 1024) { $IsOffsetBestPractice = $false } else { $IsOffsetBestPractice = $true } # as we can't tell the actual size of the file strip unit, just check all the sizes I know about foreach ($size in $stripe_units) { if ($offset % $size -eq 0) { # for proper alignment we really only need to know that your offset divided by your stripe unit size has a remainder of 0 $OffsetModuloKB = "$($offset % $size)" $isBestPractice = $true } else { $OffsetModuloKB = "$($offset % $size)" $isBestPractice = $false } [PSCustomObject]@{ ComputerName = $ogcomputer Name = "$($partition.Name)" PartitonSize = [dbasize]($($partition.Size / 1MB) * 1024 * 1024) PartitionType = $partition.Type TestingStripeSize = [dbasize]($size * 1024) OffsetModuluCalculation = [dbasize]($OffsetModuloKB * 1024) StartingOffset = [dbasize]($offset * 1024) IsOffsetBestPractice = $IsOffsetBestPractice IsBestPractice = $isBestPractice NumberOfBlocks = $partition.NumberOfBlocks BootPartition = $partition.BootPartition PartitionBlockSize = $partition.BlockSize IsDynamicDisk = $IsDynamicDisk } } } } } process { foreach ($computer in $ComputerName) { $computer = $ogcomputer = $computer.ComputerName Write-Message -Level VeryVerbose -Message "Processing: $computer." $computer = Resolve-DbaNetworkName -ComputerName $computer -Credential $Credential $Computer = $computer.FullComputerName if (-not $Computer) { Stop-Function -Message "Couldn't resolve hostname. Skipping." -Continue } #region Connecting to server via Cim Write-Message -Level Verbose -Message "Creating CimSession on $computer over WSMan" if (-not $Credential) { $cimsession = New-CimSession -ComputerName $Computer -ErrorAction Ignore } else { $cimsession = New-CimSession -ComputerName $Computer -ErrorAction Ignore -Credential $Credential } if ($null -eq $cimsession.id) { Write-Message -Level Verbose -Message "Creating CimSession on $computer over WSMan failed. Creating CimSession on $computer over DCOM." if (!$Credential) { $cimsession = New-CimSession -ComputerName $Computer -SessionOption $sessionoption -ErrorAction Ignore } else { $cimsession = New-CimSession -ComputerName $Computer -SessionOption $sessionoption -ErrorAction Ignore -Credential $Credential } } if ($null -eq $cimsession.id) { Stop-Function -Message "Can't create CimSession on $computer." -Target $Computer -Continue } #endregion Connecting to server via Cim Write-Message -Level Verbose -Message "Getting Power Plan information from $Computer." try { Get-DiskAlignment -CimSession $cimsession -NoSqlCheck $NoSqlCheck -ComputerName $Computer -ErrorAction Stop } catch { Stop-Function -Message "Failed to process $($Computer): $($_.Exception.Message)" -Continue -InnerErrorRecord $_ -Target $Computer } } } } |