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Test-DbaDiskAlignment

Mon Jan 13, 2020 6:07 pm

NAME Test-DbaDiskAlignment



SYNOPSIS

Verifies that your non-dynamic disks are aligned according to physical constraints.





SYNTAX

Test-DbaDiskAlignment [-ComputerName] <Sqlcollaborative.Dbatools.Parameter.DbaInstanceParameter[]> [[-Credential]

<Pscredential>] [[-SqlCredential] <Pscredential>] [-NoSqlCheck <Switch>] [-EnableException <Switch>]

[<CommonParameters>]





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.





PARAMETERS

-ComputerName [<Sqlcollaborative.Dbatools.Parameter.DbaInstanceParameter[]>]

The target computer or computers.



Required? false

Position? named

Default value

Accept pipeline input? False

Accept wildcard characters? false



-Credential [<Pscredential>]

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.



Required? false

Position? named

Default value

Accept pipeline input? False

Accept wildcard characters? false



-EnableException [<Switch>]

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.



Required? false

Position? named

Default value

Accept pipeline input? False

Accept wildcard characters? false



-NoSqlCheck [<Switch>]

If this switch is enabled, the disk(s) will not be checked for SQL Server data or log files.



Required? false

Position? named

Default value

Accept pipeline input? False

Accept wildcard characters? false



-SqlCredential [<Pscredential>]

Login to the target instance using alternative credentials. Accepts PowerShell credentials (Get-Credential).



Windows Authentication, SQL Server Authentication, Active Directory - Password, and Active Directory -

Integrated are all supported.



For MFA support, please use Connect-DbaInstance.



Required? false

Position? named

Default value

Accept pipeline input? False

Accept wildcard characters? false



<CommonParameters>

This cmdlet supports the common parameters: Verbose, Debug,

ErrorAction, ErrorVariable, WarningAction, WarningVariable,

OutBuffer, PipelineVariable, and OutVariable. For more information, see

about_CommonParameters (https:/go.microsoft.com/fwlink/?LinkID=113216).



INPUTS



OUTPUTS



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/lib ... .100).aspx

- Getting Partition Offset information with Powershell - http://sqlblog.com/blogs/jonathan_kehayias/archive/201

0/03/01/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/ ... er-faster/

Thanks to Jen McCown!

- Disk Performance Hands On - http://www.kendalvandyke.com/2009/02/di ... recap.html

Thanks to Kendal Van Dyke!

- Get WMI Disk Information - http://powershell.com/cs/media/p/7937.aspx

Thanks to jbruns2010!



-------------------------- EXAMPLE 1 --------------------------



PS C:\\>Test-DbaDiskAlignment -ComputerName sqlserver2014a



Tests the disk alignment of a single server named sqlserver2014a

-------------------------- EXAMPLE 2 --------------------------



PS C:\\>Test-DbaDiskAlignment -ComputerName sqlserver2014a, sqlserver2014b, sqlserver2014c



Tests the disk alignment of multiple servers



RELATED LINKS

https://dbatools.io/Test-DbaDiskAlignment