Dell DC, 3, User Manual

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Dell Manager 197
– Read-ahead specifies that the controller uses read-ahead for the
current logical drive.
– Adaptive specifies that the controller begins using read-ahead if
the two most recent disk accesses occurred in sequential sectors. If
all read requests are random, the algorithm reverts to Normal ,
however, all requests are still evaluated for possible sequential
operation.
• Cache Policy applies to reads on a specific logical drive. It does not
affect the Read-ahead cache.
– Cached I/O specifies that all reads are buffered in cache memory.
– Direct I/O specifies that reads are not buffered in cache memory.
This is the default setting. Direct I/O does not override the cache
policy settings. Data is transferred to cache and the host
concurrently. If the same data block is read again, it comes from
cache memory.
Initializing Logical Drives
You should initialize each new logical drive you configure. You can initialize
the logical drives in two ways:
• Batch Initialization. The Initialize option on the Management Menu
lets you initialize up to eight logical drives simultaneously.
• Individual Initialization. The Objects—
>
Logical Drive action menu
for an individual logical drive has an Initialize option.
Batch Initialization
Perform the following steps to initialize more than one logical drive.
1
Select Initialize from the Dell Manager Management Menu .
A list of the current logical drives appears.
2
Press the arrow keys to highlight the drives to be initialized.
3
Press the spacebar to select the desired logical drives for initialization
or press <F2> to select or deselect all the logical drives.
4
After you select the logical drives, press <F10>.
5
Select Yes at the confirmation prompt.