H3C UniServer E3200 G3, Руководство пользователя

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Read policy —Monitoring data reads, the storage controller reads sequential data that will be
requested in advance and stores the data in the cache. When the sequential data is requested,
the controller directly reads the data stored in the cache. This mechanism speeds up reads for
sequential data.
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Write policy —The storage controller stores received data in the cache and notifies the system
of the completion of data write. Without waiting for the data to be written into physical drives,
the system immediately starts the next data transmission.
The storage controller writes data stored in the cache to physical drives when the data in the
cache is accumulated to a certain amount.
Applicable scenarios
The high speed read/write cache feature is applicable to scenarios where high read/write speed is
required.
RAID information clearing on drives
About RAID information clearing
If a drive is hot swapped, RAID information remains on the drive. You must clear RAID information
on the drive before you configure the drive in a RAID array.
Applicable scenarios
The RAID information clearing feature is applicable to scenarios when you want to use a used drive
to build a RAID array.
Power fail safeguard
About power fail safeguard
A power fail safeguard module is composed of a flash card and a supercapacitor. With write cache
enabled, data stored in the cache gets lost if the server is powered down unexpectedly when power
fail safeguard does not take effect. You can enable both write cache and power fail safeguard on the
server to ensure data security:
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Data in the cache will be copied to the flash card when the server is powered down
unexpectedly.
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Data in the flash card will be written to the drives when the server is powered on.
Applicable scenarios
You can configure power fail safeguard for critical data to provide data security.