How to connect more that 8 SAS drives on SuperMicro X11SPH-nCTF

[centaur]

Hello everyone,

I have SuperMicro X11SPH-nCTF with onboard Broadcom SAS 3008 controller.

I plan to create storage spaces on server 2019 and I would like to connect more than 8 SAS drives (currently I have 8 SAS ports available).
Do I need another controller (for example AOC-S3008L-L8e) or I can expand existing one? Motherboard also has Oculink connectors which provide connectivity to NVMe SSDs and backplanes.

I plan to use total 12 or maybe 14 disks.
Six of them will be capacity tier (perhaps 8TB or 10TB) and other six or even maybe eight will be performance tier (enterprise SSD with approx 1TB, not sure yet).

Operating system is on RAID-1 SATA disks so all SAS ports are free for use

Thanks in advance.

 

[j_h_o]

You can add an expander so the onboard controller would go to an expander, and you'd connect all your drives to the expander.

Intel RES3FV288 SAS/SATA 12 Gb/s Storage Expander NEW OPEN BOX | eBay

Launch Date Q2 '14. NEW OPEN BOX - INCLUDES ALL ACCESSORIES. Expected Discontinuance Q2'23. # of Ports Internal 28. Data Transfer Rate 12 Gb/s.

www.ebay.com

Seller should accept a price considerably lower than the listed price.

 

[centaur]

In my local store, for approx 200$ I can buy new AOC-S3008L-L8e

Is there a reason why SAS expander would be a better solution in this case?

And what about Oculink connectors?
Can I use them with this supermicro cable to connect more SAS drives?

 

[j_h_o]

1. The SAS expander means the 1 controller you have onboard would be able to talk to many more drives, while giving you identical connectors to what is already on your board. It's a "cleaner" solution perhaps because all the drives are connected to the same controller. It gives you the most flexibility for the future because you'd be able to connect a lot of drives.
   
   If you want the best throughput to all the drives, you should add more/separate 12Gbps controllers. Each would have direct PCIe access, but this would come at the expense of power consumption/heat, too.
   
   If you're looking for something cheaper, you could find slower 6Gbps SAS controller to talk to the spinners. But if you want more specific suggestions, you should also share what chassis/backplane you're using and/or how the drives will be connected.
   
   I'm not sure what your goals/priorities are .
   
   
2. The OCuLink ports are for connecting NVMe drives; you won't be able to directly connect that to SAS drives.
   You can find cables that will fit, but they will only offer PCIe bus access and SAS drives will not work when connected.
   The SAS controller you have on that board is only exposed via the two SFF-8643 ports, not anything else.
   
   The cable you linked to will allow you to connect 1 NVMe drive to 1 port/per cable.

 

[centaur]

@j_h_o Thanks for detailed answer.

I have Define R6 tower and FSP TWINS PRO 700

My final goal is to connect total of 16 SAS3 12Gbps enterprise disks (8 x 3.5" spinners and 8 x 2.5" SSDs). Maybe initially I will go with 6 + 6 disks with 1+1 hot spare disk.
Spinners will have approx 200-250MB/s and SSDs will have approx 2000MB/s.
I will use HBA mode (not RAID) since I will create software defined storage.

So, it seems to me that connecting spinners to 6Gbps SAS is a great idea.
I suppose that PCI-E 2.0 card like this could do the job?

Since I also have 8 SATA ports on motherboard, maybe I will expand sds pool in the future with some more 2.5" spinners