On an R720xd connect rear flex bay to 2nd PCI HBA controller?

[khisanthax]

I have an r720xd that's running proxmox and I have truenas in a VM. I flashed the h710p mini to IT mode and connected the 12 bays via the backplane to that. I would like to use the rear 2 2.5 bays as the os drives, but it would have to be connected to a different controller so I can pass the h710p to truenas.

I know that the flex bay goes connected to the mobo for power but I'm not familiar with the cable and so I'm not sure if the end has a mini-sas that would connect to the HBA. Can I connect the rear flex bay to an LSI HBA controller in the pci slot?

I've seen one post on this forum where someone mentions they did the same, although, they didn't want to but didn't mention how or what cable they used, if any, to make that direct connection.

 

[HoneyBadger]

Hey @khisanthax

The R720XD rear "Flex Bay" uses a standard SAS SFF-8087 internal connector, shown as "Port A1" in this diagram. Check for clearance issues in case you need an angled connector, but you shouldn't have any issues connecting this to a separate HBA with a regular SFF-8087 cable.

 

[Ericloewe]

There may also be a SFF-8087 connector providing SATA from the PCH. That would save the hassle of the additional HBA.

 

[HoneyBadger]

There may also be a SFF-8087 connector providing SATA from the PCH. That would save the hassle of the additional HBA.

That's an option as well, but note that if there isn't one already included, you'll need to buy a "reverse breakout" cable that will take the individual SATA ports and combine them into the SFF-8087 form (and of course, you'll only be able to use SATA drives with this solution)

 

[khisanthax]

Hey @khisanthax

The R720XD rear "Flex Bay" uses a standard SAS SFF-8087 internal connector, shown as "Port A1" in this diagram. Check for clearance issues in case you need an angled connector, but you shouldn't have any issues connecting this to a separate HBA with a regular SFF-8087 cable.

Thanks for the confirmation, I bought both so I'm crossing my fingers it works well. It was hard for me to tell from pictures of the ports were the same as what's in the cable

 

[khisanthax]

There may also be a SFF-8087 connector providing SATA from the PCH. That would save the hassle of the additional HBA.

You mean a mini sas on the motherboard that's not controlled by the on board mini mono?

 

[Ericloewe]

You mean a mini sas

Don't call it that, it's extremely confusing and non-specific. There are some three or four popular connectors for SAS, at least, and that designation is often thrown at several of them. Call it what it is, SFF-8087.

on the motherboard that's not controlled by the on board mini mono?

Yes, it is not unusual at all to see that. I'm not sure that the R730XD has one and I don't have one to check, but the user manual should be clear enough. Judging by the Gen13 firmware on the R630, there may even be two of them, plus two SATA-style ports, for the total 10 SATA ports supported by the PCH.

 

[HoneyBadger]

Do note that Dell has a habit of disabling the onboard PCH/SATA ports on some of their boards permanently in the firmware; I'm not sure if this is the case with the R720XD, but it's a possibility.