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SAS HBA Heat?

XTREEMMAK

Newbie
Joined
Feb 8, 2016
Messages
33
Hey all,

So I'm finally in the process of upgrading my FreeNAS box to a Supermicro 846E16 Chassis which is a 24 drive case (up from my 15 drive case in my signature). This will be the first time I'm working with SAS though.

While I'm still unsure if I will be going with the 120mm fan hack that is available for this case in place of the stock fans (though I did order the SQ power supply version since I got the case barebone and will be migrating my existing motherboard over) the existing motherboard does not have SAS connections on it and for my existing setup, was using a separate SATA card and the onboard SATA. I'm currently using 13 drives but might add 6 more drives as a separate new vdev to the existing pool.

I'm thinking about just getting rid of the SATA card and using the existing two SAS connectors (the backplane is a BPN-SAS2-846EL1 and has two SFF8087 connectors coming from it) into maybe this card (https://www.ebay.com/itm/HP-H220-6Gbps-SAS-PCI-E-3-0-HBA-LSI-9207-8i-P20-IT-Mode-for-ZFS-FreeNAS-unRAID/162862201664)

This seems fine, however since I have no experience with working with SAS cards, I've been reading that these things can generate a lot of heat and have seen pictures of people adding 40mm fans to the heatsinks to keep them cool.

While I more than likely will just have one of these in the system, is cooling really a huge problem with these cards?

Just in case though, I did see a post that recommended a SFF8087 to 4x SATA breakout if I wanted to use my existing hardware, so I got two of them. However if it's better to go the SAS HBA rout then sure.
 
Last edited:

PhiloEpisteme

FreeNAS Guru
Joined
Oct 18, 2018
Messages
692
I'm thinking about just getting rid of the SATA card
This is likely a good decision

using the existing two SAS connectors (the backplane is a BPN-SAS2-846EL1 and has two SFF8087 connectors coming from it)
This is a great idea. Though, I think the EL1 version of that backplane has 3 connectors only 1 of which goes to your backplane. Check the documentation here on page 2-1. You'll notice that SEC_J0, SEC_J1, and SEC_J2 are only available in the EL2 version. Furthermore, PRIM_J1 and PRIM_J2 are used only for cascading so only PRIM_J0 will plug into your HBA. I don't think you need the EL2 version anyway though. Those extra plugs (the SEC ones) are for failover and multipath and don't really increase your bandwidth as far as I know. You can double-check with supermicro though and correct me if I'm wrong. :)

Great card, great ebay seller. 100% can recommend. If it were up to me I'd buy all of my used parts from that seller.

This seems fine, however since I have no experience with working with SAS cards, I've been reading that these things can generate a lot of heat and have seen pictures of people adding 40mm fans to the heatsinks to keep them cool.

While I more than likely will just have one of these in the system, is cooling really a huge problem with these cards?
The cards list an amount of required airflow. If you stick with the stock fans you'll almost certainly get enough airflow in there. If you're worried about it you could go the cheap-easy route and pick up one of those GPU fan brackets that attach to the top of the expansion slot and hover over the card so you can mount a fan there. I did this when I had my server in a desktop case.

Just in case though, I did see a post that recommended a SFF8087 to 4x SATA breakout if I wanted to use my existing hardware, so I got two of them. However if it's better to go the SAS HBA rout then sure.
I know nothing about the SATA card you have; but I do know that the HBA you listed is supported by FreeNAS and is well-known by this community. If I were you I'd go for the HBA if you can afford it.
 

XTREEMMAK

Newbie
Joined
Feb 8, 2016
Messages
33
Ahh ok, so I guess I only need one of the included SAS cables then. For 24 drives though at least 4TB, that should be ok right on that single HBA card, As far as I understand that documentation you posted.
 

PhiloEpisteme

FreeNAS Guru
Joined
Oct 18, 2018
Messages
692
Ahh ok, so I guess I only need one of the included SAS cables then. For 24 drives though at least 4TB, that should be ok right on that single HBA card, As far as I understand that documentation you posted.
Yup, they will be fine, that backplane is an expander backplane and will take care of the rest. There have been a lot of discussions lately on the forums about bandwidth in that scenario; and while it might seem limiting to use a single cable keep in mind that your primary limitation is likely to be your NIC which the SAS2 cable, even with only 4 lanes, will easily outclass unless you're using 40Gbps or something.
 

XTREEMMAK

Newbie
Joined
Feb 8, 2016
Messages
33

XTREEMMAK

Newbie
Joined
Feb 8, 2016
Messages
33
Yup, they will be fine, that backplane is an expander backplane and will take care of the rest. There have been a lot of discussions lately on the forums about bandwidth in that scenario; and while it might seem limiting to use a single cable keep in mind that your primary limitation is likely to be your NIC which the SAS2 cable, even with only 4 lanes, will easily outclass unless you're using 40Gbps or something.
Right and I think drive limitations as well since I'm using platter 5400 RPM SATA drives
 

PhiloEpisteme

FreeNAS Guru
Joined
Oct 18, 2018
Messages
692
Right and I think drive limitations as well since I'm using platter 5400 RPM SATA drives
WD Reds? ;)

This is why I considered both ports as an option as a note. Will check both pieces of info again:
https://www.ixsystems.com/community/threads/the-time-has-come-first-freenas-build.59000/#post-417165
I hesitate to say it, because I'm probably wrong, but I think @Chris Moore may have been mistaken in that post with respect to the using two cables to get access to 8 lanes on an EL1 backplane. Even the EL2 I think only uses the SEC_J0 for failover and multipath and doesn't give 8 lanes of bandwidth. For the EL1 the manual suggests that PRIM_J1 and PRIM_J2 are used for cascading only and not to give access to the drives themselves. I also vaguely remember seeing somewhere that someone asked supermicro about this and confirmed what I'm saying here. I'd love to be wrong though; if you contact Supermicro and clarify I'd love see their response.
 

Johnnie Black

FreeNAS Guru
Joined
May 10, 2017
Messages
743
The EL1 backplane supports dual link, Supermicro recommends connecting the HBA to PRI_J1 and PRI_J2, but it will likely work with any 2 ports.
 

PhiloEpisteme

FreeNAS Guru
Joined
Oct 18, 2018
Messages
692
The EL1 backplane supports dual link, Supermicro recommends connecting the HBA to PRI_J1 and PRI_J2, but it will likely work with any 2 ports.
oh? Looking at the manual I see only three configurations, using PRI_J0 alone or PRI_J0 to an HBA and PRI_J1 to a lower backplane. I don't see any configurations using PRI_J1 and PRI_J2. I'm looking at the manual here. Where are the recommendations you're talking about? I'd love to see the specifics.
 

PhiloEpisteme

FreeNAS Guru
Joined
Oct 18, 2018
Messages
692
Thank you very much, I appreciate being proven wrong. Hopefully @Chris Moore will forgive me.
 

XTREEMMAK

Newbie
Joined
Feb 8, 2016
Messages
33
Awesome news :) Looks like I have a path forward now.

Thanks greatly!
 
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