Users Guide

Virtual Disks
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 30 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.
NOTE:
If the boot VD is spanned across different SATA controllers, then Windows Hardware Quality Labs testing (WHQL),
DF - Reinstall with I/O Before and After (Reliability) fails in a server having two SATA controllers.
Topics:
• Virtual disk features
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 Optimize.
TRIM is applied.
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