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24 Dell EMC SC Series: Microsoft Windows Server Best Practices | 680-042-007
TRIM/Unmap is supported with the following types of virtual volumes and disks:
• The virtual hard disk format must be VHDX (dynamic or fixed)
- TRIM/Unmap is not supported with the VHD virtual hard disk format
- The guest VM OS must support TRIM/Unmap
- When the guest VM OS is Windows Server 2012 or later, from the perspective of the guest, the
VHDX must be a basic disk, formatted as NTFS
- TRIM/Unmap is not supported on a VHDX when the guest VM OS is Windows Server 2008 R2 or
earlier
3.12 Volume maintenance
Windows Server 2012 and newer automatically performs routine maintenance on volumes through the
Optimize Drives application. To open the Optimize Drives application, navigate to Control Panel >
Administrative Tools > Defragment and Optimize Drives. Alternately, right-click a volume, select the
Tools tab, and click the Optimize button.
Optimize Drives application
By default, drive optimization runs weekly on all drives (volumes) on the system. Automatic scheduling of
drive optimization can be set to run on specific volumes on a daily, weekly, or monthly basis.
On thinly-provisioned LUNs, the first thing drive optimizer attempts is slab consolidation and slab analysis
(also known as defragmentation). A slab refers to an allocation of data on the underlying LUN. On SC Series
storage, this is known as a data page. Windows will not run slab consolidation and analysis on thinly-
provisioned LUNs with a slab size of less than 8 MB. Since the page size on an SC Series array is 512 KB, 2
MB (default), or 4 MB, slab consolidation and analysis will not occur on an SC Series LUN.