I would double check that backplane uses SFF-8087 and not the fanout cables usually found on internal backplane.
Sometimes they embed sideband communications in backplane cable.
Check the connector on backplane for sideband. You need to match that up with connector on LSI.
Generally when shopping Dell Server parts you need the Generation as well as model.
For example you need backplane cable for Gen7 R620....
Here is an example of sideband cable at bottom of picture.
Hard drive backplane board for Dell PowerEdge R620 servers. Comes with all required cables.
www.ebay.com
I have that same backplane, I have the same cables from the bottom, they are connected to the side of the r620 board, enumeration of backplane:
CN-03971G-74751-
45J-1636-A00
DP/N 03971G
Sorry for my ignorance, but what does that cable have to do with the connection to the LSI controller? The backplane as you can see in the image also has two sff-8087 connectors that go to the PERC H710mini RAID controller.
Current cable
I have the LSI manual:
LSI 9207-8i man
It has two sff-8087 connectors that in my opinion have to be connected to the sff-8087 on the backplane, right where the RAID controller is currently connected, that's why my question and excuse my ignorance, those lower cables that I showed in the image of the backplane, I don't understand it at all.
Given that SFF 8087 was very common for a long time, I'd have a look on offers for used/"new old-stock" cables e.g. from supermicro, dell or hp. In your case preferably dell, as there's often some additional proprietary cabling for sideband communicacions with the backplane integrated into those cables.
But TBH I wouldn't buy anything as ancient as 92xx/SAS2008 based nowadays - SAS2 and PCIe 2.0 is a bottleneck for pretty much anything flash based and even modern spinning rust. Additionally, SAS3008 based HBAs are available absolutely dirt-cheap, so that's the absolute minimum I'd look for...
I understand your point, but this server is only for specific learning, I think I cannot put another HBA controller, since in the r620 manual only the LSI SAS 9207-8i appears as supported.
All this gave me to understand that these two server components as HBA are compatible, and I did not start to look so specifically at the cabling. I have the 10 bay r620, I think I will put 2 cheap enterprise SSDs from eBay, so I can use L2ARC in ZFS.
r620 tech manual
On page 9, I could only see in the raid controllers section, this HBA compatible with this server, possibly putting another type of more powerful HBA would end badly, I don't know.
Thanks guys.