Dell EMC PowerVault MD3400 and MD3420 Series Storage Arrays Deployment Guide

A storage array includes various hardware components, such as physical disks, RAID controller modules, fans, and power supplies, gathered into enclosures. The physical disks are accessed through the RAID controller modules.

One or more host servers attached to the storage array can access the data on the storage array. You can also establish multiple physical paths between the hosts and the storage array so that loss of any single path (for example, through failure of a host server port) does not result in loss of access to data on the storage array.

Using MDSM, you can configure the physical disks in the storage array into logical components called disk groups or dynamic disk group and then divide the disk groups into virtual disks. Disk groups are created in the unconfigured capacity of a storage array. Virtual disks are created in the free capacity of a disk group.

Unconfigured capacity comprises physical disks not already assigned to a disk group. When a virtual disk is created using unconfigured capacity, a disk group or dynamic disk group is automatically created. If the only virtual disk in a disk group is deleted, the disk group is also deleted. Free capacity is space in a disk group that is not assigned to any virtual disk.

Data is written to the physical disks in the storage array using RAID technology. RAID levels define how data is written to physical disks. Different RAID levels offer different levels of accessibility, redundancy, and capacity. You can set a specified RAID level for each disk group and virtual disk on your storage array.

For more information about using RAID and managing data in your storage solution, see the Owner’s Manual at Dell.com/support/manuals.