1. Linux... I would think that Intel provides drivers for their chipsets for the Linux OS. You'd just need to figure out exactly what the "storage controller" chipset of the Z800 is, and look that up and try the driver(s) that Intel provides. Again, I have zero experience with Linux.
2. No, there is no way to check from within BIOS because BIOS is a primative OS that is running the computer before your Linux or my Windows7Pro64 boots up. That is when the storage controller OS software drivers kick in.
3. DBAN is available as a free downloadable ISO, which can be burned by a Windows box (and maybe a Linux box?) to create a bootable CD which then can be booted from (and it runs a Linux based program), and it is running with no regard to the OS that is waiting to boot on the hard disc drive (HDD) or solid state drive (SSD). So, there is no reason you cannot use DBAN. Just burn the ISO or have a Windows friend burn the CD for you. Yes.... I had this brand new unopened server 3TB drive that would be junk if I did not try the last trick I knew, which had worked for me many times before..... DBAN, and it worked again. Yes, it did take about 3 days but I have a dedicated xw6400 utility workstation in a back room for such projects. For a 6TB.... 6 days? Try other things first.
I just posted on this again earlier today, and included a link to the HP customer advisory. You might want to contact someone like Dan_WGBU to ask him for input on whether 6TB HDDs could ever work in the Z800. He certainly said a 3TB HDD could work, and it does. I trust his input as a HP engineer fully.
4. What I was writing about was not attaching a HDD to a PCIe slot card. I was talking about using a M.2 form factor SSD attached to a passive PCIe slot interface card and using that M.2 SSD as my boot/applications drive. However, others have posted about using a fully engineered PCIe card that has miltiple SATA3 connectors so that they can attach their SATA3 drives (sitting internally) to this internal card and thereby be able to use their SATA3 HDD(s) at full SATA3 speeds in these SATA2 workstations. That is possible because the PCIe generation 2 slots are faster than SATA3 speeds, and still even faster than my M.2 SSD (which is significantly faster than SATA3).
If that type of SATA3 card is what you want you need to make sure to plug it in to a fast rather than slow PCIe slot. Your Z800 has both PCIe generation 1 and PCIe generation 2 slots (and legacy PCI). You do not ever want to use a PCIe generaton 1 slot for such a project.... it is too slow. In your Technical and Service manual you can see what slots are PCIe generation 2.
Dan once posted on some HP tested out to be good, and HP sold them at one time, but I cannot find that post. I'm quite sure such a card would require drivers..... you need to come on over to the dark side.
