Changing the Read Cache Setting
When read caching is enabled, the controller monitors 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, thereby improving
performance. You can set the Read Cache to:
• Enabled—The controller transfers data from the logical drive to its local cache in portions 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 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.
Note: For additional performance gains in read-intensive applications, you can also
use maxCache read caching. For more information, see
Changing the maxCache
Settings for a Logical Drive
on page 64.
To quickly change the read cache setting:
1. In the Enterprise View, select a controller, then select a logical drive on that controller.
2. On the ribbon, in the Logical Disk group, click Set Properties.
The Set Properties window opens.
3. In the Read Cache drop-down list, select
Enabled
or
Disabled
, as needed.
4. Click OK.
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. You can set the Write Cache to:
• Disabled (write-through)—The controller sends (or writes) the data to a disk drive, then 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 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 or zero-maintenance cache
protection module. Enabled is the default setting.
• Enabled (write-back) when protected by battery/ZMM—Similar to Enabled (write-back), but used
when the controller is protected by a zero-maintenance cache protection module. For more
information about zero-maintenance cache protection, see the Adaptec RAID Controller Installation
and User's Guide.
Note: (RAID 10, 50, and 60 only) All logical drives comprising a RAID 10/50/60 logical
device must have the same write cache setting—either all write-through or all
write-back.
To quickly change the write cache setting:
1. In the Enterprise View, select a controller, then select a logical drive on that controller.
2. On the ribbon, in the Logical Disk group, click Set Properties.
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Document No.: CDP-00278-01-A Rev. A, Issue:
maxView Storage Manager User's Guide
