Virtual Disks; Virtual Disk Features; Trim For Sata Ssds - Dell PowerEdge User Manual

A logical grouping of physical disks attached to a PERC S140 allows you to create multiple virtual disks of the same RAID levels, without
exceeding a maximum of 16 virtual disks.
The PERC S140 controller allows:
• Creating virtual disks of different RAID levels on a S140 controller.
NOTE: Ensure that you do not mix RAID levels on the same physical disks.
• Building different virtual disks with different characteristics for different applications.
• Creating virtual disks from a mix of NVMe PCIe SSD 2.5-inch SFFs and NVMe PCIe SSD adapters.
The PERC S140 controller does not allow:
• Creating a virtual disk from a mix of different types of physical disks. For example, a RAID 10 virtual disk cannot be created from two
SATA HDD physical disks and a SATA SSD physical disk. All of the physical disks must be of the same drive type (HDD/SSD/NVMe
PCIe SSDs).
• Selecting a physical disk as a dedicated hot spare if the physical disk is a different type from the physical disk of the virtual disks.
A virtual disk refers to data storage which a controller creates using one or more physical disks.
NOTE: A virtual disk can be created from several physical disks; the operating system considers it a single disk.
The capacity of a virtual disk can be expanded online for any RAID level without rebooting the operating system.

Virtual disk features

TRIM for SATA SSDs

The TRIM command allows an operating system to delete a block of data that is no longer considered in use from the SATA SSDs. TRIM
resolves the Write Amplification issue for supported operating systems. When an operating system deletes a file, the file is marked for
deletion in the file system, but the contents on the disk are not actually erased. As a result, the SSDs do not know that the Logical Block
Addressing (LBA) file previously occupied can be erased. With the introduction of TRIM, when a file is deleted, the operating system sends
a TRIM command along with the LBAs that do not contain valid data.
NOTE: The TRIM feature is supported only on pass-through SSDs.
NOTE: The TRIM feature is not supported on NVMe PCIe SSDs.
To perform TRIM on the pass-through SSDs
1 Create a volume on a pass-through SSD drive.
2 In the Windows operating system, navigate to the Defragmentation and Optimize Drive tool.
3 Select the volume created on the pass-through SSD and click the Optimize button.
The volume is trimmed.
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Virtual Disks

Virtual Disks
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