1

most raid controllers of today, while supporting large amounts of drives, have only two SFF8643 ports. here is the particular controller i am interested in. it’s pretty mainstream. (the server i am building has a gigabyte motherboard, hence the gigabyte controller)

my question is, how do you get from those two ports to, as this controller is capable of, 32 drives? the case i was thinking of is this one. (no i won’t necessarily buy it from walmart) as one can see, it has 5 SFF8643-connected back-planes for connecting the drives. what is the industry standard for making those connections?

what if one wanted to just connect 32 internal SSD’s and skip the backplane altogether? obviously it wouldn’t be as handy to replace drives, but i’m just curious.

jared

7 Spice ups
2

with no backplane you need a direct cable - these are mainly available as 4 port mini SAS/SATA to one SFF8643 - so 4 drives per connection. This is due to the fact that the SAS standard is 4 channel, so one drive per channel at 6Gbps gives full bandwidth as 24Gbps is the total of the sas connection.

Beyond that backplanes are required which often have custom daisy chaining etc. common scenarios would be one backplane per channel etc.

The case you suggest with 5 backplanes - you would connect each backplane to a port on the controller. So with 1 controller just 2 backplanes available.

1 Spice up
3

so with the case above it would limit me to 8 drives per raid controller? (four drives per back plane, two ports on raid controller) there’s no way i can expand beyond that? because 8 drives per virtual disk is rather low… the next raid controller in gigabyte’s lineup can handle over 1,000 drives. how do they expand to that level? i’m just trying to get to 20 here though…

4

All of their card spec’s talk of the SAS expander’s, yet they do not provide a product link or highlight how to use said expander.
Yes it’s getting incredibly hard to find a suitable RAID controller now days. Breakout cables were so simple

5

Most PCIe RAID controllers have 2 or 4 ports and can not go beyond 16 disks if connected directly, so a SAS expander is a must. Alternatively, you can buy a server chassis with the appropriate controller and backplane installed.

What kind of server are you building? What does your Gigabyte server MOBO has to offer in terms of disk connectivity? How many PCIe slots are present? You can go cheap using PCIe and M.2 slots SAS/SATA controllers (essentially HBA) and run some software RAID on top. Linux MDRAD or ZFS are good options depending on the planned server use case. If not familiar with Linux, you may use a prebuilt GUI appliance for that purpose Free SAN and NAS Software from StarWind or Windows Storage Spaces Storage Spaces overview | Microsoft Learn .

2 Spice ups
6

hey @supaplex. thanks for stopping by. it is a server board, so PCIe slots are sample; about 6 of them. it will be running ESXi, so hardware raid is a must. 16 disks is a little short. you mentioned a sas expander. how does that work? I assume it needs an additional PCIe slot? where can I learn more about them? do they need to be compatible with the raid controller?

7

You are very welcome.

it is a server board, so PCIe slots are sample; about 6 of them

If that is a server board, it may offer an integrated or recommended RAID controller. What does the official documentation say about available recommended storage controller options?

it will be running ESXi, so hardware raid is a must.

Not at all. You can pass through storage controllers to a virtual machine, assemble any storage pool you like (MDRAID, ZFS, LVM, whatever) and feed it back to ESXi over iSCSI or NVMeoF. Depending on your use case, such a configuration may even be better than hardware RAID.

you mentioned a sas expander. how does that work? I assume it needs an additional PCIe slot? where can I learn more about them? do they need to be compatible with the raid controller?

A SAS expander is usually a part of a large SAS backplane or SAS disk shelf, but you can also get PCIe-based ones Adaptec - Adaptec SAS Expander 82885T . They are compatible with any RAID controller as long as it is SAS, so no worries.

2 Spice ups
8

If that is a server board, it may offer an integrated or recommended RAID controller. What does the official documentation say about available recommended storage controller options?

yes. among them is the Broadcom MegaRAID 9560-16i Tri-Mode, which is what i would be shooting for. as mentioned it only has 2 ports. in this case SFF-8654. most backplanes that i’m familiar with run multiple SFF-8643 ports.

now, i assume one could take a SFF-8654 to 2x SFF-8643 breakout cable and that would equate to a total of 4x SFF-8643 ports. my question is, is i possible to get more than that? the specific case i was looking at had 5x SFF-8643 cables coming from the backplanes. that’s where i’m stuck.

Not at all. You can pass through storage controllers to a virtual machine, assemble any storage pool you like (MDRAID, ZFS, LVM, whatever) and feed it back to ESXi over iSCSI or NVMeoF. Depending on your use case, such a configuration may even be better than hardware RAID.

that is extremely interesting. thank you for that. i can now include the storage on our other servers and get even more expansion.

A SAS expander is usually a part of a large SAS backplane or SAS disk shelf, but you can also get PCIe-based ones Adaptec - Adaptec SAS Expander 82885T . They are compatible with any RAID controller as long as it is SAS, so no worries.

is it possible to integrate a, for example, broadcom sas expander right along with this controller when building a server? or are they mostly reserved for OEM’s and i would need to go with a PCIe based one. the motherboard is E-ATX. here is a link.

jared

1 Spice up
9

Appreciate the mention of our product!

Our StarWind SAN & NAS solution (available at https://www.starwindsoftware.com/san-and-nas ) can serve as an excellent traditional NAS software, provided the necessary hardware is available. It is delivered as a Linux-based virtual machine, easily deployed on your preferred hypervisor, or installed directly on bare metal using our standard installation ISO. The solution includes the same software-defined storage features as our flagship StarWind VSAN product, enabling you to fully leverage the power of hardware RAID, ZFS, or MDRAID and enhance them with our intelligent Intel Cache Acceleration Software. It also supports popular protocols such as iSCSI, SMB, NFS, and more.

Our lightweight software is easy to install and use, thanks to a user-friendly Installation Wizard and a comprehensive web-based user interface for storage management. The built-in storage profile wizard supports any storage (SATA, SAS, NVMe), automatically analyzes your hardware layout, and recommends the best configuration for your workload. Although StarWind SAN & NAS can be used for free, feel free to contact me directly via DM if you have any questions or need pricing ideas regarding support.

1 Spice up
10

I don’t think you can “integrate” additional components of choice unless the MOBO is intended for such a use case. PCIe is the obvious path here. Mostly you just purchase a server chassis that contains a MOBO already built according to the technical requirements and chassis capabilities.