Hitachi G1000, User Manual

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Also, when I/O mode of both GAD volumes is Mirror (RL), when the server
reads P-VOL data one time, only the primary system Target port and the P-
VOL record the performance information.
GAD I/O added to Performance Monitor
The amount of GAD volume I/O from and to the server that are added to
Performance Monitor depends on the GAD status, as shown the following
tables.
Table 2-15 Number of writes to GAD to be added to Performance Monitor
GAD status P-VOL S-VOL
Mirrored The sum of the following values:
•
Number of writes to the P-VOL
• Number of RIOs to the P-VOL from
the S-VOL
The sum of the following values:
•
Number of reads from the S-VOL
• Number of RIOs to the S-VOL from
the P-VOL
Mirroring Number of writes to the P-VOL Number of RIOs to the S-VOL from the
P-VOL
Suspended (when
the P-VOL has the
latest information)
Number of writes to the P-VOL Not counted*
Suspended (when
the S-VOL has the
latest information)
Not counted* Number of writes to the S-VOL
Blocked Not counted* Not counted*
* Reads and writes by a server are illegal requests and cause an error. However, they could be counted
as I/O.
Table 2-16 Number of reads from GAD to be added to Performance Monitor
GAD status P-VOL S-VOL
Mirrored Number of reads from the P-VOL Number of reads from the S-VOL
Mirroring Number of reads from the P-VOL Not counted*
Suspended (when
the P-VOL has the
latest information)
Number of reads from the P-VOL Not counted*
Suspended (when
the S-VOL has the
latest information)
Not counted* Number of reads from the S-VOL
Blocked Not counted* Not counted*
* Reads and writes from a server are illegal requests and cause an error. However, they could be
counted as I/O.
2-20
System requirements
Hitachi Virtual Storage Platform G1000 Global-Active Device User Guide