Univide UniWorkstation 5548, Руководство пользователя

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5.2.2.4 Integrated Mirroring Firmware
This section describes features of the LSI Logic Integrated Mirroring (IM) firmware, which supports up to two IM
volumes per LSI Logic SAS controller.
5.2.2.4.1 Host Interface
The IM host interface uses the Message Passing Interface, as described in the Fusion-MPT Message Passing
Interface Specification. Through the Fusion-MPT interface, the host OS has access to the IM volume as well as
the physical disks.
5.2.2.4.2 Resynchronization with Concurrent Host I/O Operation
The IM firmware allows Host I/Os to continue on the IM/IME volume while the volume is being re-synchronized in
the background. Resynchronization is attempted after a hot spare is activated due to a physical device failure, or
after a hot swap has occurred to a physical disk in the IM or IME volume.
5.2.2.4.3 Metadata Support
The firmware supports metadata, which describes the IM/IME logical drive configuration stored on each member
disk. When the firmware is initialized, each member disk is queried to read the stored metadata in order to verify
the configuration. The usable disk space for each member disk is adjusted down to leave room for this data.
5.2.2.4.4 Hot Swapping
The IM firmware supports hot swapping. The hot-swapped disk is automatically resynchronized in the background,
without any host or user intervention. The firmware detects hot swap removal and disk insertion.
Following a hot swap event, the firmware readies the new physical disk by spinning it up and verifying that it has
enough capacity for the mirrored volume. The IM firmware resynchronizes all hot-swapped disks that have been
removed, even if the same disk is re-inserted. In a two-disk mirrored volume, the IM firmware marks the hot-
swapped disk as the secondary disk and marks the other mirrored disk as the primary disk. The firmware
resynchronizes all data from the primary disk onto the new secondary disk.
5.2.2.4.5 SMART Support
The IM firmware enables Mode 6 SMART on the member disks in the mirrored volume. Mode 6 SMART requires
each physical disk to be polled at regular intervals. If a SMART ASC/ASCQ code is detected on a physical disk in
the volume, the firmware processes the SMART data, and the last received SMART ASC/ASCQ is stored in non-
volatile memory. The IM/IME volume does not support SMART directly, since it is just a logical representation of
the physical disks in the volume.
5.2.2.4.6 Hot Spare Disk
One disk can be configured as a global hot spare disk, which protects data on the one or two volumes configured
on the controller. If the IM firmware fails one of the mirrored disks, the firmware automatically replaces it with
the hot spare disk. The IM firmware then resynchronizes the mirrored data. The IM firmware is automatically
notified when the failed disk has been replaced, and the firmware then designates that disk as the new hot spare.
5.2.2.4.7 Media Verification
The IM firmware supports a background media verification feature that runs at regular intervals when the IM/IME
volume is in optimal mode. If the verification command fails for any reason, the other disk’s data for this segment
is read and written to the failing disk in an attempt to refresh the data. The current Media Verification Logical
Block Address is written to non-volatile memory occasionally to allow Media Verification to continue approximately
where it left off prior to a power-cycle.