SES-2/SGPIO sideband

alt_nick

n00b
Joined
Jul 14, 2007
Messages
8
I've been working on retrofitting an old SCSI Powervault to SAS/SATA. (Yes, silly, but fun!)
The plan is to use an adaptec 3805, switch from internal mini-SAS (SFF 8087) to external mini-SAS (SFF 8088) at the host and back to internal mini-SAS at the backplane and fan out from there.

Will SES-2/SGPIO sidebands persist through the cable changes?

I've been trying trying to find information about it myself, but half of it seems to be conflicting.
I'd assume internal and external would use the same pinouts, but sidebands seem to use vendor-specific pins so I could see them being dropped when needing greater error-resistance in external cabling.

If anyone has seen information about receiving SES-2/SGPIO with a microcontroller or found a place with standalone SGPIO-controllers for sale I'd also be interested ;)
 

UICompE02

SCSI Master
Joined
Jul 16, 2001
Messages
866
Unfortunately, none of the external SAS cables provide the sideband signals that the SGPIO signals are typically wired to on the internal connectors.

What most vendors do in that case is use a SAS expander that can emulate a SES/SEP device and send the enclosure commands in-band to that emulated device.

Alternatively, most SAS expanders support SGPIO as well and allow access to the SGPIO register set via in-band SMP requests.
 

alt_nick

n00b
Joined
Jul 14, 2007
Messages
8
Thanks for clearing it up.
Looks like I'll be taking an out-of-band approach, SAS expanders don't seem like something you can wire together yourself ;)
 
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