HP XP Racks - Manual (Page 42)

This storage system applies when the dynamic I/O path control function is
disabled.
Path status transition
Each of the online and offline statuses described in Performing Failovers and
Failbacks Using Path Switching on page 2-14 is further subdivided into
several statuses. The path statuses (the online path statuses and offline path
statuses) are explained below.
The online path status
The online path statuses are as follows:
• Online
I/Os can be issued normally.
• Online(E)
An error has occurred on the path, but none of the other paths that
access the same LU are in the Online status.
If none of the paths accessing a particular LU are in the Online status,
one of the paths is changed to the Online(E) status. This ensures that
the LU can be accessed through at least one path.
The (E) means error, which indicates that an error has occurred on the
path from some previous operation.
The offline path status
The offline path statuses are as follows:
• Offline(C)
The status in which I/O cannot be issued because the offline operation
was executed. For details on the offline operation, see offline (Places
Paths Offline) on page 6-6 .
The (C) indicates the command attribute, which indicates that the path
was placed offline by using the command.
• Offline(E)
The status indicating that an I/O could not be issued on a given path,
because an error occurred on the path.
The (E) means error.
•
Online(S) #
The paths to the primary volume (P-VOL) in the HAM environment have
recovered from an error, but I/O to the P-VOL is suppressed.
•
Online(D) #
The paths to the primary volume (P-VOL) in an HAM environment have
recovered from an error, but I/O to the P-VOL is suppressed. If an error
occurs in all the paths to a secondary volume (S-VOL), the status of the
P-VOL paths will be automatically changed to the Online status. To
2-20
HDLM Functions
Hitachi Dynamic Link Manager (for AIX) User Guide