Oracle SG-XPCIESAS-R-INT-Z, Installation Manual

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92 Sun StorageTek SAS RAID HBA Installation Guide • March 2010
Understanding Drive Segments
A drive segment is a disk drive or portion of a disk drive that is used to create an
array. A disk drive can include both RAID segments (segments that are part of an
array) and available segments. Each segment can be part of only one logical device at
a time. If a disk drive is not part of any logical device, the entire disk is an available
segment.
Nonredundant Arrays (RAID 0)
An array with RAID 0 includes two or more disk drives and provides data striping ,
where data is distributed evenly across the disk drives in equal-sized sections.
However, RAID 0 arrays do not maintain redundant data, so they offer
no data
protection .
Compared to an equal-sized group of independent disks, a RAID 0 array provides
improved I/O performance.
Drive segment size is limited to the size of the smallest disk drive in the array. For
instance, a array with two 250 GB disk drives and two 400 GB disk drives can create
a RAID 0 drive segment of 250 GB, for a total of 1000 GB for the volume, as shown in
this figure.