Thin Provisioning and Trim Storage Overview


Updated: May 4, 2012

Applies To: Windows Server 2012

This topic discusses just-in-time allocations (also known as thin provisioning) and the ability to reclaim storage that is no longer needed (also known as trim), including benefits and requirements and an overview of the technologies.

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Sophisticated storage solutions offer just-in-time allocations (also known as thin provisioning) and the ability to reclaim storage that is no longer needed (also known as trim). Windows Server 2012 integrates with these sophisticated storage solutions to enable organizations to get the most out of their storage infrastructures.

Thin provisioning and trim are enabled by default in Windows Server 2012, and have the following requirements:

  • Storage infrastructure that complies with the certification that is required for Windows Server 2012 

  • Standards-compliant hardware for identification

To confidently deploy sophisticated storage solutions that support just-in-time allocation, you need to know that you can provision additional capacity as needed. Windows Server 2012 identifies thinly provisioned virtual disks, provides standardized notifications when use thresholds are crossed, and provides a platform that enables applications to give up storage when it is no longer needed, thereby ensuring maximal use.

The following capabilities are included:

  • Identification. Windows Server 2012 uses a standardized method to detect and identify thinly provisioned virtual disks, thereby enabling additional capabilities delivered by the storage stack that is provided in the operating system and through storage management applications.

  • Notification. When configured physical storage use thresholds are reached, Windows Server 2012 notifies the administrator through events, which enables the administrator to take appropriate action as soon as possible. These events can also be used for automated actions by sophisticated management applications, such as Microsoft System Center.

  • Optimization. Windows Server 2012 provides a new API that lets applications return storage when it is no longer needed. NTFS issues trim notifications in real time when appropriate. Additionally, trim notifications are issued as part of storage consolidation (optimization), which is performed regularly on a scheduled basis.


    Processing trim commands can reduce performance of some of the storage hardware because it may delay servicing of reads and writes while servicing a trim notification.