Changing The Stripe Size; Changing The Write Cache Setting; Changing The Read Cache Setting - Adaptec ICP5045BL User Manual

Changing the Stripe Size

The stripe size is the amount of data (in KB) written to one partition before the controller
moves to the next partition in a logical drive.
Stripe size options vary, depending on your controller. Normally, the default stripe size
provides the best performance.
For RAID 6 and RAID 60 logical drives, the more disk drives there are in the logical drive, the
fewer the stripe size options.

Changing the Write Cache Setting

The write cache setting determines when data is stored on a disk drive and when the controller
communicates with the operating system.
Disabled (write-through)—The controller sends (or writes) the data to a disk drive, then
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sends confirmation to the operating system that the data was received. Use this setting
when performance is less important than data protection.
Enabled (write-back)—The controller sends confirmation to the operating system that the
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data was received, then writes the data to a disk drive. Use this setting when performance is
more important than data protection and you aren't using a battery-backup cache.
Enabled is the default setting.
Note:
(RAID 10, 50, and 60 only) All logical drives within a RAID 10/50/60 logical drive must have
the same write cache setting—either all write-through or all write-back.
To quickly change the write cache setting:
1
Click the logical drive you want.
2
In the menu bar, select Actions, click Configure write cache, then select Enabled or
Disabled as required.
The write cache setting is changed.

Changing the Read Cache Setting

When read caching is enabled, the controller monitors the read access to a logical drive and, if it
sees a pattern, pre-loads the cache with data that seems most likely to be read next, increasing
performance.
Enabled—The controller transfers data from the logical drive to its local cache in portions
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equal to the stripe size. Use this setting for the best performance when workloads are
steady and sequential. Enabled is the default setting.
Disabled—The controller transfers data from the logical drive to its local cache in portions
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equal to the system I/O request size. Use this setting for the best performance when
workloads are random or the system I/O requests are smaller than the stripe size. (For more
information about system I/O requests, refer to your operating system documentation.)
To quickly change the read cache setting:
1
Click the logical drive you want.
2
In the menu bar, select Actions, click Configure read cache, then select Enabled or
Disabled as required.
The read cache setting is changed.
Chapter 6: Modifying Your Direct Attached Storage
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