MSI X2-109 v1 - Manual (Page 63)

Configuration Commands 4-11
Version 2.0 Copyright © 2006 by LSI Logic Corporation. All rights reserved.
4.7.3 Add RAID 10 Configuration
Use the command in Table 4.13 to add a RAID 10 configuration to the
existing configuration on the selected adapter. For RAID levels 0, 1 or 5,
see
Section 4.7.1, “Add RAID 0, 1 or 5 Configuration.”
Description Configures each physical disk in Unconfigured-Good state as RAID 0 on this
controller.
The options {WT |WB} {NORA | RA | ADRA} {Direct | Cached} must be entered
in the sequence that is shown.
• WT : Used to select Write-through caching, in which a write transaction is
considered to be complete when all the data has been written to the disk cache.
• WB : Used to select Write-back caching, in which the write transaction is complete
only when the data has been written to the disk.
• NORA : Used to select Normal Read Ahead caching, which specifies that the
controller reads only the requested data and does not read ahead for the current
logical drive.
• RA : Used to select Read Ahead caching, which specifies that data is read
sequentially ahead of the data that is actually requested and is stored in a cache.
If the additional read-ahead data is then requested, it can be read faster from the
cache than from the disk directly. Read-Ahead supplies sequential data faster, but
is not as effective when accessing random data.
• ADRA : Used to select Adaptive Read Ahead, which specifies that the controller
begins using Read Ahead caching if the two most recent disk accesses occurred
in sequential sectors. If all read requests are random, the algorithm reverts to No
Read Ahead; however, all requests are still evaluated for possible sequential
operation.
If you select Read Ahead, there is a danger that data could be lost if the power
fails before the cached data is written to disk.
• Direct : Used to specify that the controller does not buffer reads in cache
memory. Data is transferred to cache and the host concurrently. If the same data
block is read again,
it comes from cache memory.
• Cached : Used to specify that the controller buffers all reads in cache memory.
• {-strpszM} : Used to specify the size of the segments written to each drive in the
configuration. You can set the stripe size to 64 Kbytes.
Table 4.12 Configure Each Disk as RAID 0 (Cont.)
Table 4.13 Add RAID 10 Configuration
Syntax CmdTool –CfgSpanAdd -R10| –Array0[E0:Sn] –Array1[E0:Sn] [...] [{WT |
WB}] [{NORA | RA | ADRA}] [{Direct | Cached}] [{-strpszM}] -aN