"Even using h310 in passthrough mode for mdam on linux, if raid controler failed, i have to put the same card with same firmware to not loose everything" I don't believe passthrough mode writes any metadata to the drives, so in theory, you would not need an H310 controller to read the drives on another controller (although you may need to adjust the boot device/drivers on the image "offline" to be able to boot it from another controller), and the controller just would need to be the same or newer than the old controller (although even older firmware *may* not be a problem). I don't use passthrough - I always use the H7xx controllers - so I can't say for certain. "im afraid too by h310 performances" Yeah, they aren't great controllers, but they do support passthrough. If you want performance, get the H710 controller. "I use raid controler on DCs and i'm not relaxed but it was impossible without on dell r710" Sure it was possible. You could have 1) had "no" controller and managed the disks individually as AHCI devices, or 2) used an H200 controller, which also supports passthrough. You just couldn't use SAS disks in AHCI (again, not sure if that has changed on the R720).
Hello, I'm trying to find answers to my questions. Do a software raid configuration is possible on R720 with SAS disks ? Moreover I don't understand the purpose of these connectors.(cf picture);[IMAGE]R720 motherboard  
Software RAID on R720 with SAS disks