B
Appendix B
RAID Technology - Understanding Disk Arrays and Virtual Disks
A disk array consists of the physical disks that are connected to a controller.
A virtual disk is data storage created by a controller from one or more physical disks. The virtual disk is viewed by the operating system as a single disk.
The Dell PowerEdge RAID Controller (PERC) S100 controller and PERC
S300 controller allows:
•SAS HDD (PERC S300 controller only), SATA HDD, and/or SATA SSD (PERC S100 controller only) physical disks to
•Physical disks of the same type (SAS HDD, SATA HDD, SATA SSD) but of different capacities.
•Virtual disks to be at different RAID levels on the same controller, but not supported on the same group of physical disks.
Because some RAID levels enhance performance while others improve reliability, it is important to consider your needs when planning a virtual disk configuration.
The ability of the controller to provide online expansion to virtual disks across multiple physical disks and controllers becomes extremely valuable when storage expansion is a requirement.
Appendix B
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