topic Re: General question on SAS (daisy chain) in General

General question on SAS (daisy chain)

Pierrot Robert — Fri, 18 Jul 2008 14:30:55 GMT

Hi,

I have a server with a single external SAS port (HP SC44Ge Host Bus Adapter) which is currently connected to an external Ultrium tape drive.

I know that with SCSI you can daisy chain devices. Is it the same with SAS ? Could I buy an external SAS drive array with IN and OUT ports and daisy chain the tape drive ?

Thanks.

Re: General question on SAS (daisy chain)

Uwe Zessin — Fri, 18 Jul 2008 16:17:33 GMT

SAS is a radial (star topology) interconnect, not a bus. There are widgets called (external) 'expanders' or 'SAS switches', but I doubt that they are supported by HP and I don't think they are cost-effective for your need.

Re: General question on SAS (daisy chain)

Curtis Ballard — Mon, 28 Jul 2008 21:55:10 GMT

Most SAS arrays will have a SAS expander built into them which will allow hooking another array behind the first but the SC44Ge only supports disk on that port.