Dell PowerEdge User Manual

Contents

Dell PowerEdge User Manual Manual pdf 14 page image

Virtual DisksA logical grouping of physical disks attached to a PERC S140 allows you to create multiple virtual disks of the same RAID levels, withoutexceeding 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 twoSATA HDD physical disks and a SATA SSD physical disk. All of the physical disks must be of the same drive type (HDD/SSD/NVMePCIe 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 featuresTRIM for SATA SSDsThe TRIM command allows an operating system to delete a block of data that is no longer considered in use from the SATA SSDs. TRIMresolves the Write Amplification issue for supported operating systems. When an operating system deletes a file, the file is marked fordeletion 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 BlockAddressing (LBA) file previously occupied can be erased. With the introduction of TRIM, when a file is deleted, the operating system sendsa 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 SSDs1 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.314 Virtual Disks