I am sorry that you are offended. I do wish you a nice day.
Hi,
To clarify the misunderstanding and explanation.
ZFS is a software raid where it looks for drives available for you to group.
If you use raid from bios/controller ZFS will only see the raid group as a single drive. This causes complications where the hardware raid is making drives consisting of many and ZFS will see it as a single drive.
you only need to worry about JBOD mode when you have a Raid/SAS controller with 30 drives attached and want to use ZFS. The reason for this is that most raid controllers will only forward raid groups by default. So setting your raid controller mode to JBOD forwards all disks for ZFS to see.
ACHI mode on motherboards negate the need for JBOD.
Essentially you need to think of layers. If the RAID is set in hardware the Software raid cannot see the individual disks in the raid group. This will end up a mess as you have nested your Raid on ZFS raid. you can imagine the complications and possible data loss.
There are cases where hardware raid is better than ZFS in write performance, but in order to achieve it you will need High level Cached controllers which will cost thousands.
I have basically simplified what is going on and hope this helps.
Thanks, however this is actually the misunderstanding. In actual fact, according to my research (I haven’t tested it), this is incorrect. The first step of enabling RAID mode in the BIOS does not (as you put it) make a single drive. The second step where the array is created with a utility (or sometimes in the BIOS) is what makes a single drive. The hardware is still visible as individual drives and there is no bios raid controller in the sense that you’re talking about. This is actually why I was asking the question, if the BIOS does not in fact create a single drive, what actually is it doing?
Research so far indicates that it disables some features but you ARE able to create a ZFS array and ZFS will see the individual drives. However, ZFS will be disadvantaged as there is an additional translation layer and the missing ATA commands are useful.
By all accounts, the correct thing is to NOT enable RAID in the BIOS as we have all known including myself, which I feel the need to continue pointing out as everyone seems to think I’m some kind of noob.
As there was not any actual facts in peoples answers, I went on a little quest to see what evidence I could find of which there hasn’t been much. But there has been a few sources explaining that certain features of the ATA command set are disabled - and these features are valuable for ZFS. Sadly some people before you are behaving like ML and only remembering the last few tokens of this thread when answering. The irony lol.
Anyway, in summary, the effective action to take is the same as your answer, however from what I’ve been able to find, ZFS will indeed see individual drives when they’re set to RAID mode. Something I can’t test until I’m back home in about a month. Understanding this was what made me question my original beliefs. And what we have now done is re-affirmed them with just a little deeper understanding which is nice. Thanks for your reply.