Lenovo ThinkServer RD240 MegaRAID SAS Software User Guide - Page 351

current write, policy, default write, device ID, device port, count, drive cache, drive group

Page 351 highlights

current write policy default write policy device ID device port count drive cache policy drive group drive state configuration for a drive group (for example, a specific arrangement of drive group members on the device I/O buses). The copyback operation can be run automatically or manually. Typically, a drive fails or is expected to fail, and the data is rebuilt on a hot spare. The failed drive is replaced with a new drive. Then the data is copied from the hot spare to the new drive, and the hot spare reverts from a rebuild drive to its original hot spare status. The copyback operation runs as a background activity, and the virtual drive is still available online to the host. A virtual drive property that indicates whether the virtual drive currently supports Write Back mode or Write Through mode. • In Write Back mode the controller sends a data transfer completion signal to the host when the controller cache has received all of the data in a transaction. • In Write Through mode the controller sends a data transfer completion signal to the host when the drive subsystem has received all of the data in a transaction. A virtual drive property indicating whether the default write policy is Write Through or Write Back. In Write Back mode the controller sends a data transfer completion signal to the host when the controller cache has received all of the data in a transaction. In Write Through mode the controller sends a data transfer completion signal to the host when the drive subsystem has received all of the data in a transaction. A controller or drive property indicating the manufacturer-assigned device ID. A controller property indicating the number of ports on the controller. A virtual drive property indicating whether the virtual drive cache is enabled, disabled, or unchanged from its previous setting. A group of drives attached to a RAID controller on which one or more virtual drives can be created. All virtual drives in the drive group use all of the drives in the drive group. A drive property indicating the status of the drive. A drive can be in one of the following states: B-3

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B-3
configuration for a drive group (for example, a specific arrangement of
drive group members on the device I/O buses). The copyback operation
can be run automatically or manually.
Typically, a drive fails or is expected to fail, and the data is rebuilt on a
hot spare. The failed drive is replaced with a new drive. Then the data is
copied from the hot spare to the new drive, and the hot spare reverts
from a rebuild drive to its original hot spare status. The copyback
operation runs as a background activity, and the virtual drive is still
available online to the host.
current write
policy
A virtual drive property that indicates whether the virtual drive currently
supports Write Back mode or Write Through mode.
In Write Back mode the controller sends a data transfer completion
signal to the host when the controller cache has received all of the
data in a transaction.
In Write Through mode the controller sends a data transfer
completion signal to the host when the drive subsystem has received
all of the data in a transaction.
default write
policy
A virtual drive property indicating whether the default write policy is Write
Through or Write Back. In Write Back mode the controller sends a data
transfer completion signal to the host when the controller cache has
received all of the data in a transaction. In Write Through mode the
controller sends a data transfer completion signal to the host when the
drive subsystem has received all of the data in a transaction.
device ID
A controller or drive property indicating the manufacturer-assigned device
ID.
device port
count
A controller property indicating the number of ports on the controller.
drive cache
policy
A virtual drive property indicating whether the virtual drive cache is
enabled, disabled, or unchanged from its previous setting.
drive group
A group of drives attached to a RAID controller on which one or more
virtual drives can be created. All virtual drives in the drive group use all
of the drives in the drive group.
drive state
A drive property indicating the status of the drive. A drive can be in one
of the following states: