Note About Media Error - Hitachi HF-W7500 65 Feature Manual

2.8.2 Note about media error

Media error is a status where there is a problem in data integrity while the RAID status is
normal. If read errors occur at the copy source drive during a rebuild process, the rebuild
process will complete but the sector data that could not be read is already lost, indicating a
data integrity problem.
<Handling a media error as a failure>
The severity of this data integrity problem depends on whether those bad sectors with
read errors are actually used. If those bad sectors are used, there is a real problem in data
integrity. But if not, that is not a problem at all.
This is why this equipment allows you, depending on how the system is operated, to
select whether a media error is reported. In the default factory settings, a media error is
not reported.
Use the RAID configuration control command (raidctrl) to select whether a media error
is reported. (For details, see "5.3 RAID Configuration Control Command (raidctrl)".)
A media error can be reported in the following ways:
(1) Event notification
(2) Outputs on the status display digital LEDs
(3) Remote notification
(4) Alarm lamp
(5) Message box
(6) MCALL contact of the RAS external contacts interface
Note that, regardless of the setting for whether a media error is reported, you can check
whether media errors occurred in the following ways:
(7) Hardware status window
(8) The hfwRaidStat function in the RAS library
(9) RAID configuration control command (raidctrl)
2. ITEMS MONITORED BY THE RAS FEATURE
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