Dell PowerVault MD3620i Owner's Manual - Page 41

RAID Levels RAID levels determine the way in which data is written to physical disks. Different RAID levels provide different levels of accessibility, redundancy, and capacity. Using multiple physical disks has the following advantages over using a single physical disk: • Placing data on multiple physical disks (striping) allows input/output (I/O) operations to occur simultaneously and improve performance. • Storing redundant data on multiple physical disks using mirroring or parity supports reconstruction of lost data if an error occurs, even if that error is the failure of a physical disk. Each RAID level provides different performance and protection. You should select a RAID level based on the type of application, access, fault tolerance, and data you are storing. The storage array supports RAID levels 0, 1, 5, 6, and 10. The maximum number of physical disks that can be used in a disk group depends on the RAID level: • 96 for RAID 0, 1 and 10 • 30 for RAID 5 and 6. RAID Level Usage To ensure best performance, you should select an optimal RAID level when you create a system physical disk. The optimal RAID level for your disk array depends on: • Number of physical disks in the disk array • Capacity of the physical disks in the disk array • Need for redundant access to the data (fault tolerance) • Disk performance requirements RAID 0 RAID 0 uses disk striping to provide high data throughput, especially for large files in an environment that requires no data redundancy. RAID 0 breaks the data down into segments and writes each segment to a separate physical disk. Planning: MD3600i Series Storage Array Terms and Concepts 41