HP XP7 Storage - Manual (Page 38)

If the Thunder 9500V series, or Hitachi AMS/WMS series is being used, HDLM
will select the path to be used next from among the various paths that access
the same LU, starting with owner paths, and then non-owner paths.
For example, in Figure 2-10 Path Switching on page 2-18 , the owner
controller of an LU is CHA0, and access to the LU is made via only one path
(A). After that access path (A) is placed offline, the first choice for the
switching destination is the other path connected to CHA0 (B). If an error
also occurs on that path (B), then the next possibility for a path comes from
one of the two paths (C or D) connected to CHA1.
When the Lightning 9900V series, Hitachi USP series, Universal Storage
Platform V/VM series, Virtual Storage Platform series, VSP G1000 series,
Hitachi AMS2000 series
# , Hitachi SMS series # , HUS100 series # , or HUS VM is
being used, all the paths are owner paths. This means that all the paths that
are accessing the same LU are possible switching destinations. For example,
in Figure 2-10 Path Switching on page 2-18 , the LU is accessed using only
the one path (A). However, after that path is placed offline, the switching
destination can come from any of the other three paths (B, C, or D).
#
This storage system applies when the dynamic I/O path control function is
disabled.
Figure 2-10 Path Switching
2-18
HDLM Functions
Hitachi Dynamic Link Manager (for Windows®) User Guide