[CentOS] LSI MegaRAID 320-2E PCIe RAID Controller

Fri Feb 4 01:29:32 UTC 2011
John R Pierce <pierce at hogranch.com>

On 02/03/11 5:23 PM, Hugh E Cruickshank wrote:
> From: John R Pierce Sent: February 3, 2011 17:14
>> On 02/03/11 5:06 PM, Hugh E Cruickshank wrote:
>>> I will reconsider the need for all three arrays and see if I can go
>>> with the PCI-X cards.
>> If this is SAS stuff, you can generally daisy chain a few trays of
>> drives, at the expensive of total available IO bandwidth (eg, fewer
>> SAS channels are being shared by more drives)
> Unfortunately it is SCSI 3 (Ultra320) which, in itself, is "chainable"
> however I believe that there may be a limitation based on the SCSI ID
> of the individual drives. I will have to do some experimentation to
> see if this is possible.
>
> Thanks for your suggestion. It is not one I had thought of as I am
> so used to limiting one array to one controller.

parallel scsi supports 15 max devices plus the controller makes 16.   
and often there is a SES backplane controller using a target ID leaving 
just 14 drives per channel/controller.