Automatic Failbacks - Hitachi XP P9500 User Manual

that path is placed offline, the switching destination can come from any of the
other three physical paths (B, C, or D).
Paths are switched in units of physical paths. Therefore, if an error occurs in a
path, HDLM switches all the other paths that run through the same physical
path.
Figure 2-8 Path Switching

Automatic Failbacks

When a path recovers from an error, HDLM can automatically place the
recovered path back online. This function is called the automatic failback
function.
In order to use the automatic failback function, HDLM must already be
monitoring error recovery on a regular basis.
When the Thunder 9500V Series, or Hitachi AMS/WMS series is being used,
HDLM selects the path to use from online owner paths, and then from online
non-owner paths. Therefore, if an owner path recovers from an error and
HDLM automatically places the recovered path online while any non-owner
path is in use, the path in use will be switched to the recovered owner path.
When the Lightning 9900 Series, Lightning 9900V Series, Hitachi USP,
Universal Storage Platform V/VM, Virtual Storage Platform, Hitachi AMS2000
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HDLM Functions
Hitachi Dynamic Link Manager User Guide (for Solaris(R))