PlatinumRAID Owner’s Manual
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3.1.3 Capacity
Enter the desired capacity size to fit your volume, up to a maximum of the available remaining
capacity displayed. Any remainder capacity will be available for other volumes.
TERABYTE AND LARGER VOLUMES
Standard SCSI allows for 1 byte Command Descriptor Blocks (CDB), limiting the maximum addressable
storage to TB per lun. If the total usable capacity of the RAIDset exceeds TB, an additional volume
must be defined. On host operating systems supporting extended (1 byte) CDB addressing, the
PlatinumRAID U0 can be set to 1 byte CDB operation to allow up to TB maximum addressable
capacity per LUN. Please see Section .1 of this chapter for more information
!
3.1.4 Volume Initialization Mode
PlatinumRAID features both foreground and background initialization modes for RAID 3 and
RAID 5 volumes. In background mode, the initialization proceeds as a background task and
the volume set is fully accessible for system reads and writes without requiring a reboot and
waiting for the initialization completion. Furthermore, the RAID volume set is also protected
against a single disk failure while initialing. Background initialization takes longer to complete
and host disk access will be slower during the initialization process. Foreground Initialization
must be completed before the volume set ready for system accesses, but the format is faster.
3.1.5 Volume Stripe Size
This parameter sets the size of the segment written to each disk in a RAID 0, 1, 3, or 5 logical
drive. You can set the stripe size to 4 KB, 8 KB, 16 KB, 32 KB, 64 KB, or 128 KB. A larger
stripe size produces better-read performance for mostly sequential reads. For better random
reads performance, select a smaller stripe size.
3.1.6 Volume Cache Mode
PlatinumRAID supports Write-Through and Write-Back Caching algorithms. In the Write-
Back caching method, modifications to data in the cache aren’t copied to the cache source
until absolutely necessary, whereas a Write-Through cache performs all write operations in
parallel -- data is written to the storage and the cache memory simultaneously. Write-back
caching yields somewhat better performance than write-through caching because it reduces
the number of write operations to disk, but is also more prone to data loss due to service
interruptions.
3.1.7 Tagged Command Queuing
The Command Tag (Drive Channel) function controls the command tag queuing support
for the drive channels. Tagged Command Queuing is useful for enhancing overall system
performance under multi-tasking operating systems. This function should normally remain
enabled unless instructed otherwise by MicroNet support.
3.1.8 Max SCSI Speed
The RAID subsystem supports up to 320MB/S as the highest data transfer rate. You may need to
adjust this parameter if you are experiencing SCSI bus stability issues.
3.1.9 SCSI Channel (Reserved)
PlatinumRAID supports one SCSI channel. Do not modify this parameter.
6-RAID Controls-Web Interface