Optimize-VHD

Optimize-VHD

Optimizes the allocation of space used by virtual hard disk files, except for fixed virtual hard disks.

Syntax

Parameter Set: Default
Optimize-VHD [-Path] <String[]> [-AsJob] [-ComputerName <String[]> ] [-Mode <VhdCompactMode> ] [-Passthru] [-Confirm] [-WhatIf] [ <CommonParameters>]

Detaillierte Beschreibung

The Optimize-VHD cmdlet optimizes the allocation of space in or more virtual hard disk files, except for fixed virtual hard disks. The Compact operation is used to optimize the files. This operation reclaims unused blocks as well as rearranges the blocks to be more efficiently packed, which reduces the size of a virtual hard disk file.

To use Optimize-VHD, the virtual hard disk must not be attached or must be attached in read-only mode.

The compact operation can succeed without reducing the file size, if no optimization is possible.

Parameter

-AsJob

Specifies that the cmdlet is to be run as a background job.

-ComputerName<String[]>

Specifies one or more Hyper-V hosts on which a virtual machine is to be optimized. NetBIOS names, IP addresses, and fully-qualified domain names are allowable. The default is the local computer — use “localhost” or a dot (“.”) to specify the local computer explicitly.

-Mode<VhdCompactMode>

Specifies the mode in which the virtual hard disk is to be optimized. For a VHD disk, the default mode is Full. For a VHDX disk, the default mode is Quick. Valid modes are as follows:

--Full scans for zero blocks and reclaims unused blocks. (Allowable only if the virtual hard disk is mounted read-only.)

--Pretrimmed performs as Quick mode, but does not require the virtual hard disk to be mounted read-only. The detection of unused space is less effective than Quick mode (in which the virtual hard disk had been mounted read-only) because the scan cannot query information about free space in the NTFS file system within the virtual hard disk. Useful when the VHDX-format file has been used by operating system instances that are at least Windows 8 or Windows Server 2012, or when this cmdlet has already been run on a .vhdx file in Retrim mode.

--Prezeroed performs as Quick mode, but does not require the virtual hard disk to be mounted read-only. The unused space detection will be less effective than if the virtual hard disk had been mounted read-only as the scan will be unable to query information about free space in the NTFS file system within the virtual hard disk. Useful if a tool was run previously to zero all the free space on the virtual disk as this mode of compaction can then reclaim that space for subsequent block allocations. This form of compaction can also be useful in handling virtual hard disk containing file systems other than NTFS.

--Quick reclaims unused blocks, but does not scan for zero blocks. (Allowable only if the virtual hard disk is mounted read-only.)

--Retrim sends down retrims without scanning for zero blocks or reclaiming unused blocks. (Allowable only if the virtual hard disk is mounted read-only.)

-Passthru

Specifies that an object is to be passed through to the pipeline representing the virtual hard disk to be optimized.

-Path<String[]>

Specifies one or more paths to the dynamic or differencing virtual hard disk files to be optimized.

-Confirm

Sie werden vor dem Ausführen des Cmdlets zur Bestätigung aufgefordert.

-WhatIf

Zeigt, was geschieht, wenn das Cmdlet ausgeführt wird. Das Cmdlet wird nicht ausgeführt.

<CommonParameters>

Dieses Cmdlet unterstützt die allgemeinen Parameter: -Verbose, -Debug, -ErrorAction, -ErrorVariable, -OutBuffer, -OutVariable. Weitere Informationen finden Sie unter about_CommonParameters (https://go.microsoft.com/fwlink/p/?LinkID=113216).

Eingaben

Der Eingabetyp ist der Typ der Objekte, die über die Pipeline an das Cmdlet übergeben werden können.

Ausgaben

Der Ausgabetyp ist der Typ der Objekte, die vom Cmdlet ausgegeben werden.

Beispiele

Example 1

Runs the compact operation in Full mode. (If the VHDX-format file is not attached as read-only prior to the operation, it will default to Prezeroed mode.)

PS C:\> Optimize-VHD –Path c:\test\dynamic.vhdx –Mode Full

Example 2

Runs the compact operation in Retrim mode. (If the VHDX-format disk is not mounted as read-only prior to the operation, running the cmdlet returns an error.)

PS C:\> Optimize-VHD –Path c:\test\dynamic.vhdx –Mode Retrim

Example 3

Runs the compact operation in Quick mode. (If the VHDX-format file is not attached as read-only prior to the operation, it defaults to Pretrimmed mode.)

PS C:\> Optimize-VHD –Path c:\test\dynamic.vhdx –Mode Quick