No. Your least cost option is two cards. One for the external ports and one for the internal ports. Any four port card is going to be extra cost and there are no four port cards that I am aware of that split the connection two external and two internal although you can take two internal ports and cable them to an external bracket.
I figured as much, but I wanted to be sure. More often than not, if I can't find something in ~30 minutes, it usually means I'm using the wrong search terms or I'm looking for something that doesn't exist.
I think you are working on a misunderstanding. Please give more explanation of what you have and what it is you are trying to accomplish.
For example, why are you planning for spares and why are you planning for more than one pool. It sounds like the design is questionable.
Little backstory... The primary purpose of this FreeNAS build is to act as a media server. It replaces a Windows10 JBOD system, and to make the transition on the cheap, I bought 4x10TB disks to start with. My plan had been to leapfrog the disks from the W10 system into the FN build after their data had been transfer over, thereby expanding the FN build as I went along.
After inserting the 4 initial disks into the FN build, I realized my first folly. I started looking into FN a few years ago, and became more serious about a build right around the time the tweet came out about expanding vdevs (sometime in 2017, IIRC). Classic look before you leap situation. I assumed that functionality was ready, which was a penalizing error in judgement.
At around this same time, I also noticed the warning message that read that expanding a pool meant using only similar vdevs. Second misconception, even bigger mistake. But, I was running out of space in the W10 system and I was anxious to get going with the FN build.
So, instead of waiting another month or two to save up for more 10TB drives and RAM, I just decided to breakup my initial plan of one large pool into 4 separate pools. I bought an additional set of 10TB disks (bringing my total to 6) to complete my first pool, and then started transferring the data over.
I now have 3 pools with 6 drives each (1x6x10TB and 2x6x4TB), and although I've strayed from my initial plan, 3 storage locations is much easier to manage than 11.
In the W10 system, there is now a Storage Space I setup with 3x4TB disks. I use that to record over-the-air HDTV, which is then processed with
MCEBuddy. This system also downloads content off of streaming sites (e.g. Netflix and Amazon) with
PlayOn.
I haven't been happy with the transfer speeds from one system to the other, so I might start thinking about moving those disks into the FN build. I just don't know yet if the DVR will function properly when writing over a Samba connection.
This new pool would be in addition to housing spares in the W10 system, so I'm looking at needing to add ~ 8 disks or so via some SAS method. I'm fully aware I've taken the "duct tape" equivalent route with all of this, but that's part of the fun for me ;)
Are you trying to add a JBOD?
If you are, keep it simple
You need a SAS Controller (I use a M1015) and a 8087 to 8088 pass thru (If you controller has no 8088 port)
If you don't have a spare 8087 port you simply add a $15 expander
I have one of these and was planning to add another:
LSI SAS9211-8i
I'm intrigued by the Expander you referenced. First I've learned of such thing, and I love the price. Perhaps I don't need another LSI card after all...
....
After doing a little bit of research, I have more questions I'll need to answer before moving forward with that solution.
Would you happen to have any pictures of how both of your towers are wired (both inside and out, and to one another)?