Hey I recently bought a supermicro 36 bay server. A 847E16-R1400LPB if it matters. And had a question about the sas cables.
https://imgur.com/a/1Fp9nfm
From what I can see there's 4 hookups for the front backplane, and 8 on the rear with only 4 hooked up. With 4 free ports. And only 4 cables to plug into a raid card.
From what I can tell it looks like two of the front backplane cables goes to the rear backplane, with only two from each free to plug into a raid card.
I'm coming from a r710 so I'm still a bit of a newbie here. So just want to know if it's all good. I need to get new cables anyhow, as my gear is 8087. So I'll need to buy new cables. Just need to see if I need 4, 8, 12, or what's up.
Thanks for any and all help!
Was wondering what way is possible to connect my supermicro backplane BPN-SAS3-846EL1 to my motherboard.
I see that the motherboard (H13SSL-N) has 3 MCIO x8 ports. 2 are NVME ports with 2 channels each and 1 MCIO can be also be another 2 channel NVME or 8 channel SATA.
Is it possible to use a MCIO x8 to 2 x SFF-8643?
If that doesn't work, what should I use to connect my 24 Bay SATA drives in a JBOD configuration?
I was looking at the Supermicro BPN-SAS3-826EL1 backplane, and came across the BPN-SAS3-826EL1-N4 which has some NVMe capabilities. When would this be useful? (I'm a bit of of date when it comes to disk technology). Are there 2.5" or 3.5" NVMe drives with a SAS connector? Is NVMe faster than SAS3? Do you need a special HBA to go with it?
What do I need to do to use 12 HDDs with that backplane?
You connect ONE SAS CABLE from your HBA to the backplane. DONE.
There is nothing more. THe backplane is handling the distribution of hard disc signals. SAS is like a storage network protocol and the backplane is like a switch - with every port to one HDD and the outputs for chaining for the next backplane.
Updating for the updated question:
I'd like to use SATA drives (not SAS), and I already have a LSI 9361-8i connected to the backplane, using two cables with SFF-8643 connectors at each end. That way the controller is seeing 8 drives. Now I'd like to know how I can use the remaining 4 drives.
The solution to that is to LEARN THE TECHNOLOGY. You ahve serious misconecptions. There is no two cables for SATA.
Let's start:
You can use SATA discs in a SAS backplane. SAS implements a SATA passthrough protocol so SATA discs show up.
The 2 cables are NOT for 4 discs each. RTFM. SAS is a network protocol. For uptime and more bandwidth, SAS discs support 2 uplink connections. Hence two cables. This is EVERY DISCS IS CONNECTED TO BOTH CABLES AT THE SAME TIME.
SATA discs are not. THey only support one uplink. So, RTFM aside which may decide to split that, IIRC, all discs connect to ONE CABLE. You can literally have hundreds of discs on one SAS link. When you use SATA, all connect to ONE of the two cables, in most backplanes that is link 1. Link 2 is not used then as NONE OF THE DISCS CONNECT TO IT.
So, the whole "4 one one, 4 on the other" is a clear sign of lacking ANY manual reading for SAS, sorry. There is no "4 discs". A SAS link is equal to 4 SATA links in bandwidth, but it still runs a combined network protocol that the backplane handles. Grab an introductory book on how SAS works. If the last 4 drives do not show up, this has NO correlation to the cabling - it is either a bad connection on the discs, a defective board, bad jumper settings somewhere OR - bad power cable connectivity. THere are a LOT of power inputs in a SAS board because of the limits of every MOLEX connector, so discs are grouped with separate power supplies provided. If everythign works as perfect, ONE cable (all that is needed) will provide connectivity for hundreds of discs. Again, this is a NETWORK protocol.
If you have the -EL1 backplane, you should be able to see all 12 drives, even with a single cable from the RAID card to the expander backplane. If you don't, something's wrong with the backplane or the drives, as the previous answer states.
To clarify some of the other subquestions:
- A single cable carries 4 12Gbps SAS lanes. If connected to a passive backplane without an expander, it can only be used for 4 drives. With an expander though, it just provides bandwidth between the RAID card and the expander, and the number of drives that can be used depends on how many ports are attached to the expander (including both the directly attached drives as well as any downstream backplanes attached via the cascading ports). There will be limits on the total number of drives, but they're usually large enough (eg 128+) to not matter.
- The -EL1 backplane has 2 "upstream" connections not for dual-port SAS, but to provide higher bandwidth to the RAID card. For HDDs this won't really matter, it might matter if you install SSDs in all the drive bays. The -EL2 backplane has two expanders and supports dual-port SAS drives, as well as dual RAID controllers, for high availability.