On Thu, Jul 11, 2024 at 01:16:22PM +0000, Drew Weaver wrote:
Hello,
We would like to repurpose some Dell PowerEdge R750s for a Ceph cluster.
Currently the servers have one H755N RAID controller for each 8 drives. (2 total) The N variant of H755N specifically? So you have 16 NVME drives in each server?
I have been asking their technical support what needs to happen in order for us to just rip out those raid controllers and cable the backplane directly to the motherboard/PCIe lanes and they haven't been super enthusiastic about helping me. I get it just buy another 50 servers, right? No big deal. I don't think the motherboard has enough PCIe lanes to natively connect all the drives: the RAID controller effectively functioned as a expander, so you needed less PCIe lanes on the motherboard.
As the quickest way forward: look for passthrough / single-disk / RAID0 options, in that order, in the controller management tools (perccli etc). I haven't used the N variant at all, and since it's NVME presented as SCSI/SAS, I don't want to trust the solution of reflashing the controller for IT (passthrough) mode. -- Robin Hugh Johnson Gentoo Linux: Dev, Infra Lead, Foundation President & Treasurer E-Mail : robbat2@gentoo.org GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85 GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136