Hitachi XP P9500 User Manual page 35
Hitachi dynamic link manager software user guide for windows (6.6) (hit5201-96006, november 2011)
Hide thumbs
Also See for XP P9500:
- User manual (746 pages) ,
- User manual (188 pages) ,
- User manual (574 pages)
Table of Contents
Advertisement
•
The Extended Round Robin algorithm
•
The Least I/Os algorithm
•
The Extended Least I/Os algorithm
•
The Least Blocks algorithm
•
The Extended Least Blocks algorithm
The above algorithms are divided into two categories, which differ in their
processing method. The following describes both of these processing
methods:
The Round Robin, Least I/Os, and Least Blocks algorithms
These algorithms select which path to use every time an I/O is issued.
The path that is used is determined by the following:
Round Robin
¢
The paths are simply selected in order from among all the connected
paths.
Least I/Os
¢
The path that has the least number of I/Os being processed is
selected from among all the connected paths.
Least Blocks
¢
The path that has the least number of I/O blocks being processed is
selected from among all the connected paths.
The Extended Round Robin, Extended Least I/Os, and Extended Least Blocks
algorithms
These algorithms determine which path to allocate based on whether the
data of the I/O to be issued is sequential with the data of the I/O that
was issued immediately beforehand.
If the data is sequential, the path used will be the one to which the data
of the I/O that was issued immediately beforehand was distributed.
However, if a specified number of I/Os has been issued to a path,
processing switches to the next path.
If the data is not sequential, these algorithms select the path to be used
each time an I/O request is issued.
Extended Round Robin
¢
The paths are simply selected in order from among all the connected
paths.
Extended Least I/Os
¢
The path that has the least number of I/Os being processed is
selected from among all the connected paths.
Extended Least Blocks
¢
The path that has the least number of I/O blocks being processed is
selected from among all the connected paths.
Table 2-5 Features of the Load Balancing Algorithms on page 2-16
the features of the load balancing algorithms.
Hitachi Dynamic Link Manager User Guide (for Windows(R))
HDLM Functions
describes
2-15
Advertisement
Table of Contents
