Dell POWERVAULT MD3600F - Manual (Page 47)

Planning: MD3600f Series Storage Array Terms and Concepts 47
RAID 10
RAID 10, a combination of RAID 1 and RAID 0, uses disk striping across
mirrored disks. It provides high data throughput and complete data
redundancy. Utilizing an even number of physical disks (four or more) creates
a RAID level 10 disk group and/or virtual disk. Because RAID levels 1 and 10
use disk mirroring, half of the capacity of the physical disks is utilized for
mirroring. This leaves the remaining half of the physical disk capacity for
actual storage. RAID 10 is automatically used when a RAID level of 1 is
chosen with four or more physical disks. RAID 10 works well for medium-
sized databases or any environment that requires high performance and fault
tolerance and moderate-to-medium capacity.
Segment Size
Disk striping enables data to be written across multiple physical disks. Disk
striping enhances performance because striped disks are accessed simultaneously.
The segment size or stripe element size specifies the size of data in a stripe
written to a single disk. The MD3600f Series array supports stripe element sizes
of 8 KB, 16 KB, 32 KB, 64 KB, 128 KB, 256 KB, and 512 KB. The default stripe
element size is 128 KB.
Stripe width, or depth, refers to the number of disks involved in an array
where striping is implemented. For example, a four-disk group with disk
striping has a stripe width of four.
NOTE: Although disk striping delivers excellent performance, striping alone does
not provide data redundancy.
Virtual Disk Operations
Virtual Disk Initialization
Every virtual disk must be initialized. Initialization can be done in the
foreground or the background. A maximum of four virtual disks can be
initialized concurrently on each RAID controller module.
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