Fujitsu ETERNUS Multipath Driver V2, Руководство пользователя

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Chapter 3 Multipath Driver Functions and Operation
3.1 Path Management
FUJITSU Storage ETERNUS Multipath Driver V2 User’s Guide for Linux
Copyright 2014 FUJITSU LIMITED P2U3-0031-15ENZ0
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I/O request not-ready paths may be classified into the following three unready statuses:
Table 3.2 Online path sub-states
These path status transitions are shown in the following figure.
Figure 3.1 Path status transitions
Unready status Description
fail
• I/O errors have been detected on the path, and Auto Path Check has judged it to be
unusable.
• Fail paths are checked every 10 minutes for replacement of the failed parts.
• If the Auto Path Check detects no problem, the status reverts to warning.
• After replacement of the failed parts, the "iompadm restart" command may be
used to instantly return the path to active/standby status.
• Fail paths will never be used for I/O.
• [fail "error information"] is displayed by the "iompadm info" command (details of
the error appears in "error information").
fatal fail
• Result of the Auto Path Check is constantly switching back and forth between
normal and abnormal, so the appropriate checks cannot be performed.
• Fatal fail paths are not checked.
• After replacement of the failed parts, the "iompadm restart" command must be
used to return the path to active/standby status.
• Fatal fail paths will never be used for I/O.
• [fail "forcible fail"] is displayed by the "iompadm info" command.
stop
• Path has been disconnected by the "iompadm change" command.
• Stop paths are not checked.
• The "iompadm restart" command must be used to return the path to active/standby
status.
• Stop paths will never be used for I/O. However, if no active or standby path is
available, a stop path may be returned to active status for use
(unless all paths are stop status).
• [stop "stop by command"] is displayed by the "iompadm info" command.
active
standby
fatal fail
(1)
(2)
(3) (4)
(7)
fail
stop
warning
(6)
(5)
(8)