Working With Physical And Logical Disks; Disk Group Configuration - Dell PowerVault MD3200i Series Technical Manualbook

DELL PowerVault MD3200i/MD3220i Technical Guide Book
about a selected problem, and recovery steps to follow for the selected problem.
Physical and Logical Disks

Disk Group Configuration

A disk group is a set of physical disks that the controller
logically groups together to provide one or more virtual
disks to a host. Each disk group is comprised of the
same drive technology (i.e. SAS, near-line SAS or SSD)
and has an assigned RAID level. While multiple RAID
levels can be intermixed in a single MD3200i series
storage array, each disk group has a single RAID level.
The number of physical disks that make up a disk group
can be selected manually or automatically. When using
the MD Storage Manager software's automatic
configuration option, disk groups will be configured
balancing the load across as many physical disk channels
and physical disk modules as possible. This ensures maximum protection and performance.
MD Storage Manager software also provides the ability to dynamically add additional physical disks to
existing disk groups. Existing virtual disks are then re-striped across all physical disks in the newly
expanded disk group. This takes place while the disk group and all its virtual disks remain online and
accessible for I/O.
The selection of the RAID configurations is equally critical for each application to meet the desired
data availability, performance or capacity requirements. And like physical disk types and configuration
settings, the MD3200i series of arrays support the intermixing of RAID configurations to provide
maximum flexibility and utilization. RAID 5 is generally considered the best balance of cost,
performance and reliability. The table below outlines the tradeoffs of the various supported RAID
configurations.
Working with
Disk Group A
Disk
Disk Disk
2
1
Disk
4
3
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