the odd numbered slots in the IT firmware are normal, the dell backplane is ordered oddly and the dell firmware knows this and accounts for it so the slot numbers make sense, but the IT firmware does not so it shows the weird ordering of the dell backplane.
I have no idea why it's not showing all the drives, nobody else has had this and no matter what I try I can't reproduce it. Are you mixing SAS and SATA drives by chance? It should be able to handle this, but I'm not sure what else to investigate at this point. Are there other drives you can try, or try not mixing drive models just to rule it out? (eg try only the 7 identical drives). Can you see these missing drives in other systems? I would check that as well, I suppose they could have some weird RAID partition/header leftover from the RAID firmware that only the dell raid firmware will show, granted I don't think that would stop them from showing up as devices completely
I have no idea why it's not showing all the drives, nobody else has had this and no matter what I try I can't reproduce it. Are you mixing SAS and SATA drives by chance? It should be able to handle this, but I'm not sure what else to investigate at this point. Are there other drives you can try, or try not mixing drive models just to rule it out? (eg try only the 7 identical drives). Can you see these missing drives in other systems? I would check that as well, I suppose they could have some weird RAID partition/header leftover from the RAID firmware that only the dell raid firmware will show, granted I don't think that would stop them from showing up as devices completely