Asus PIKE 2208 - Manual (Page 25)

ASUS PIKE 2208 2-11
◊ Always Read Ahead: This enables read ahead capability, which
allows the controller to read sequentially ahead of requested data and
to store the additional data in cache memory, anticipating that the data
will be needed soon. This speeds up reads for sequential data, but
there is little improvement when accessing random data. This is the
default.
• Write Policy: Specify the write policy for this virtual drive:
◊ Write Through: 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.
◊ Always Write Back: In Writeback 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. This setting is recommended
in Standard mode.
• 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:
◊ Unchanged: Leave the current drive cache policy unchanged. This is
the default.
◊ Enable: Enable the drive cache.
◊ Disable: Disable the drive cache.
• 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 terabytes, gigabytes,
megabytes, or kilobytes. 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.
8. Click Accept to accept the changes to the virtual drive definition, or click
Reclaim to return to the previous settings.