Gateway 840 VT-100, User Manual

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Viewing access statistics
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Total Read Commands
Since Reset This is a count of the total number of read accesses that
have occurred since the statistics were reset or the
controller was last powered on.
Total Read Transfer Since
Reset This is a count of the total number of 512-byte blocks
that have been read since the statistics were reset or
the controller was last powered on.
Alignment This is the percentage of commands whose address is
aligned on the specified address boundary. The
alignment of a command from a host system is
determined by the command’s address. In an optimal
system, a write of one chunk of data would reside
exactly within a chunk on one disk. However, if this is
not the case, this write will be split up into two separate
writes to two different data drives. This of course will
have a negative effect on performance. To overcome
these problems, you can, with more sophisticated
operating systems, set the access size and alignment
to an optimal value. These statistics can help you to
tune the operating system.
Statistic Description