Media Patrol - NEC Express5800 Series User Manual

3.11 Media Patrol

The media patrol reads data in the following HDDs entirely. As HDDs can be deteriorated with
age, faults in the HDDs may be detected only when they are accessed. By reading data in HDDs
routinely, the media patrol enables such faults to be detected as early as possible. This enables
the early appropriate action.
HDDs configuring RAID
HDDs set to spares
IMPORTANT:
Some access may occur during media patrol. Then the media patrol is interrupted temporarily
until the access is completed. Accordingly, the media patrol can hardly cause the system
performance to be decreased. Because media patrol has lower priority than other tasks in the
system, it is recommended to use the media patrol in the environment where your system is
subject to comparatively small load in any period including the night.
For the media patrol, follow the procedure below:
1. Click the Physical Drive View icon in the Tree View.
2. Click the Media Patrol Schedule tab in the Management Window.
3. Click [Start Now].
Media Patrol starts.
The media patrol is not done for HDDs which are not
configured in logical drives. Specify HDDs not
configured as spare disks previously.
The media patrol can detect HDD media errors as
early as possible and only repair HDDs which are the
members of a redundant RAID. However, the media
patrol does not have the feature of checking the
consistency with parity.
The function starts media patrol and runs though the
HDDs you specified. If you specify a task scheduling,
media patrol will regularly start at the specified date
and time and also run through the HDDs specified.
The function does not perform endlessly.
If a media error is detected in a HDD being a member
of non-redundant RAID, The error sector is registered
to BSL.
Error during media patrol
If an unrecoverable error is detected during media
patrol, the error count in the Media Patrol Information
is incremented. The error count indicates the
accumulated value.
If more than 21 errors are detected in a single media
patrol, the HDD is entered into the offline status.
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