Dell DC, 3, User Manual

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Glossary 245
Stripe Size— The amount of data contiguously written to each disk. You can
specify stripe sizes of 4 KB, 8 KB, 16 KB, 32 KB, 64 KB, and 128 KB for each
logical drive. For best performance, choose a stripe size equal to or smaller
than the block size used by the host computer.
Stripe Width— The number of hard drives across which the data are striped.
Striping— Segmentation of logically sequential data, such as a single file, so
that segments can be written to multiple physical devices in a round-robin
fashion. This technique is useful if the processor can read or write data
faster than a single disk can supply or accept it. While data is being
transferred from the first disk, the second disk can locate the next segment.
Data striping is used in some modern databases and in certain RAID
devices.
Stripe Size— The amount of data contiguously written to each disk. Also
called "stripe depth." You can specify stripe sizes of 4 KB, 8 KB, 16 KB, 32
KB, 64 KB, and 128 KB for each logical drive. A larger stripe size produces
improved read performance, especially if most of the reads are sequential.
For mostly random reads, select a smaller stripe size.
Stripe Width— The number of drives across which data is striped.
Terminator— A resistor connected to a signal wire in a bus or network for
impedance matching to prevent reflections, e.g., a resistor connected across
signal wires at the end of a SCSI cable.
Wide SCSI— A variant on the SCSI-2 interface. Wide SCSI has a 16-bit
bus, double the width of the original SCSI-1.
Write-Back— In Write-Back caching mode, the controller sends a data
transfer completion signal to the host when the controller cache has
received all the data in a disk write transaction. Data are written to the disk
subsystem in accordance with policies set up by the controller. These
policies include the amount of dirty/clean cache lines, the number of cache
lines available, elapsed time from the last cache flush, and others.
Write-Through— In Write-Through caching, the controller sends a data
transfer completion signal to the host when the disk subsystem has received
all the data in a transaction. The controller cache is not used.