Dell PowerEdge R6515 and Dell drives

Hello @Alef,

Let's see if I can answer your answers:

1. Do I need to purchase Dell branded NVMe drives to boot and use the system ? Or can I use Samsung / Intel ones ?

You always need to use Dell certified drives, no need to use directly branded dell drives but to make sure you are using Enterprise certified drives. So, for the example of NVMe drives, just make sure they are compatible with the server. My advice is always ask for recommendations when buying the server (direct Dell Sales representative or a partner).

2. Do I need to also purchase Dell branded SATA drives to install the OS (GNU/Linux Debian) and boot the system ?

Same as above, you need to always use Dell certified drives. Not all drives are compatible.

3. Is this server able to use pci-4 (full speed) with the NVMe drives ?

That might depend on the base configuration of the server in the time you are buying and configuring it.

4. Do I still need a Perc controller (for example the H740P) even if just using two NVMe drives ? I'm ok with using GNU/Linux software raid-1.

No, some server models can use the software PERC. But you need to make sure when buying the server that the software PERC support NVMe. Again, my suggestion is that you transfer your needs and question to the sales representative when buying the server. You can check for Dell Partners here: https://dell.to/3RXKqU8

Regards.