The OCuLink port on X11SDV motherboard

[saurav]

I have a couple of n00b questions about the OCuLink port which is present on SuperMicro's X11SDV boards:

1. Is it ok to connect the disks from the backplane of FreeNAS mini to the OCuLink port with a cable like this?

https://store.supermicro.com/cable/50cm-oculink-sata-cbl-sast-0933.html

Will this provide ZFS the "direct access" to disks that it likes to have, unlike raid cards, etc.? IOW, is this just like SAS-to-SATA breakout?

2. Does the OCuLink port have any other benefits (other than lesser cables), like future expansion with external multi-disk enclosures?

I'm still reading up, but so far I haven't found my answers.

Thanks,
Saurav.

 

[Chris Moore]

OCuLink

Perhaps you are using the wrong terminology. I don't see any such name of a connector.
https://www.supermicro.com/products/motherboard/Xeon/D/X11SDV-8C-TP8F.cfm

https://www.supermicro.com/QuickRefs/motherboard/d/QRG-2007.pdf

https://www.supermicro.com/manuals/motherboard/d/MNL-2007.pdf

 

[saurav]

Sorry, should have been more specific about the part#:

https://www.supermicro.com/products/motherboard/Xeon/D/X11SDV-8C_-TLN2F.cfm

The port right above the left-bottom mounting hole is the OCuLink port.

 

[danb35]

...and it's properly known as a SFF-8611 connector, though the only reference I can find to those is in the context of the so-called "OCuLink" (with no indication what's up with the weird capitalization). The product page says all 8 SATA ports run off the SoC, so I'd expect it should be fine--but I'm afraid I don't have any direct experience.

 

[Redcoat]

From https://blog.exxactcorp.com/need-know-oculink-technology/


OCuLink stands for “Optical Copper (Cu) Link” and is a PCI Express (PCIe) interconnect system. It was created by the standards body for the PCI interface (PCI-SIG) and the latest OCuLink 2 is considered an alternative to Thunderbolt. OCuLink 2 will have up to 16 GT/s (8 GB/s total for x4 lanes).

It features a small cable form factor that is optimized for internal and external enclosure usage and is capable of providing up to 32 Gbps in each direction within a four lane configuration. The OCuLink 2 connectors work as a two-piece, metal-to-metal contact system with Molex’s NanoPitch connector and cable assembly system. The cable doesn’t carry clock signals or power, which allows for low-cost cables, connectors, and ports due to the lack of complex shielding requirements.

Usage for OCuLink include internal and external PCIe attached storage, PCIe I/O expansion, and A/V equipment. In server applications, it is being used as a connection from the motherboard or add-in-card to HDD midplane, an alternative to HDminiSAS. With NVMe U.2 drives, the OCuLink protocol can be used over the U.2 connector.

 

[saurav]

I could not find any external storage storage solution that allow for expansion, I.e. attaching multiple disks, using this standard.

Also, Thunderbolt already provides a 40Gbps link. Why bother with another standard for external storage/expansion?

In server applications, it is being used as a connection from the motherboard or add-in-card to HDD midplane

I guess this partly answers my first question, but how safe is this for zfs/freenas?

 

[Chris Moore]

I guess this partly answers my first question, but how safe is this for zfs/freenas?

I would go with an older model board because this is likely not supported yet. Too new.

 

[CoachDitka]

Sorry, should have been more specific about the part#:

https://www.supermicro.com/products/motherboard/Xeon/D/X11SDV-8C_-TLN2F.cfm

The port right above the left-bottom mounting hole is the OCuLink port.

I am attempting to use the X11SDV-12C-TLN2F OCuLink Port with a Western Digital SN750 NVME M.2 SSD. The SSD is mounted to a SIlverstone SDP12, and I am using a Dilinker OCuLink 4i SFF-8611(PCI-Express/Host) to HD Mini SAS SFF-8643 SSD Data Active cable to connect the OCuLink port to the Silverstone sled.

When booting into Windows Setup, I am unable to find the drive. Working on some troubleshooting steps, but wanted to add my experience.

I have flashed the BIOS to the latest version (1.3), toggled through both NVME firmware settings in the BIOS North Bridge, and also tried UEFI only and Hybrid boot options. No joy yet.

 

[CoachDitka]

Solved my own problem - I replaced the SDP12 sled and Dilinker cable with a Startech U2M2E125 sled and the OCuLink cable that came with the board. Now I'm up and running with NVME. Next challenge - Hope that the right-angle OCuLink extension cable I ordered is low enough that I can install my RAID card.