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.