Lenovo ThinkServer RD240 MegaRAID SAS Software User Guide - Page 89

IO Policy, Drive Cache, Disable BGI, Select Size, Accept, Reclaim, Direct, Cached, Enable, Disable

Page 89 highlights

• IO Policy: The IO Policy applies to reads on a specific virtual drive. It does not affect the read ahead cache. ◊ Direct: In direct I/O mode, reads are not buffered in cache memory. Data is transferred to the cache and the host concurrently. If the same data block is read again, it comes from cache memory. This is the default. ◊ Cached: In cached I/O mode, all reads are buffered in cache memory. • Drive Cache: Specify the drive cache policy: ◊ Enable: Enable the drive cache. ◊ Disable: Disable the drive cache. ◊ NoChange: Leave the current drive cache policy as is. This is the default. • Disable BGI: Specify the background initialization status: ◊ No: Leave background initialization enabled. This means that a new configuration can be initialized in the background while you use WebBIOS to do other configuration tasks. This is the default. ◊ Yes: Select Yes if you do not want to allow background initializations for configurations on this controller. • Select Size: Specify the size of the virtual drive in megabytes. Normally, this would be the full size for RAID 0 shown in the Configuration panel on the right. You may specify a smaller size if you want to create other virtual drives on the same drive group. 6. Click Accept to accept the changes to the virtual drive definition, or click Reclaim to return to the previous settings. 7. Click Next when you are finished defining virtual drives. The Configuration Preview screen appears, as shown in Figure 4.6. Creating a Storage Configuration 4-13

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Creating a Storage Configuration
4-13
IO Policy:
The IO Policy applies to reads on a specific virtual drive.
It does not affect the read ahead cache.
Direct
:
In direct I/O mode, reads are not buffered in cache
memory. Data is transferred to the cache and the host
concurrently. If the same data block is read again, it comes
from cache memory. This is the default.
Cached
:
In cached I/O mode, all reads are buffered in cache
memory.
Drive Cache:
Specify the drive cache policy:
Enable
: Enable the drive cache.
Disable
: Disable the drive cache.
NoChange
: Leave the current drive cache policy as is.
This is the default.
Disable BGI:
Specify the background initialization status:
No
: Leave background initialization enabled. This means that
a new configuration can be initialized in the background
while you use WebBIOS to do other configuration tasks.
This is the default.
Yes
: Select
Yes
if you do not want to allow background
initializations for configurations on this controller.
Select Size:
Specify the size of the virtual drive in megabytes.
Normally, this would be the full size for RAID 0 shown in the
Configuration panel on the right. You may specify a smaller size if
you want to create other virtual drives on the same drive group.
6.
Click
Accept
to accept the changes to the virtual drive definition, or
click
Reclaim
to return to the previous settings.
7.
Click
Next
when you are finished defining virtual drives.
The Configuration Preview screen appears, as shown in
Figure 4.6
.