Discovering FakeRAID in the Real World
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@bnrstnr said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
So it DOES come from the motherboard?
It has too, there is no where else for it to reside and run.
All of the disks are also connected to the motherboard directly via the SATA ports.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
What @scottalanmiller and I are saying is your motherboard, the one where you went in and did CTRL + <something> is a pixie-dust magic version of RAID.
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
It's FakeRAID because it isn't like Windows RAID (what is the implemented title for Windows RAID?) and it certainly isn't the MD version of SoftwareRAID from the Linux world.
Software RAID are implemented post OS startup and installation if you are lucky you might do it pre-install (XCP-NG is experimenting with Software RAID levels at installation time atm RAID1 only)
MDADM is post install, so you'd run from a single disk, and then you'd have your additional disks that you want to create an array from. (1 disk to boot 4 disks for storage). sOBR10 the 4 disks and you'd be off to the races.
It's something built and distributed to make you think you have the industry standard versions of RAID.
The utility you've used on this board is controlled from the Motherboard, thus it's FakeRAID. It "does" RAID but it's such a bad idea to use it that you'd be better off adding a third disk and using proper SoftwareRAID for wherever you want your data to reside.
The thing is, FakeRAID is RAID... nobody gives a shit here what kind of RAID it is. Don't listen to Scott, the kind of RAID it was I never was debating. That was all stuff he was shoving in my mouth.
The fact of the matter is that FakeRAID or not, it's coming from the motherboard... which most motherboards give you.
Are you getting the FakeRAID from the powersupply? No. From the motherboard? Yes.
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@obsolesce said in Discovering FakeRAID in the Real World:
Are you getting the FakeRAID from the powersupply? No. From the motherboard? Yes.
So yes, 99% of motherboards DO have raid (even if it's FakeRAID, it's still RAID). This was my original point.
If you go back and read my posts, you'll see the type of RAID was never part of my point. That was what Scott was saying was my point, confusing everyone else including himself.
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@obsolesce said in Discovering FakeRAID in the Real World:
The thing is, FakeRAID is RAID... nobody gives a shit here what kind of RAID it is.
But this is critical to know the difference. Raid that is provided by some utility that is baked into the motherboard is predominantly more risky than the other options you have. (software and hardware).
Because the utility is way under developed (and used) compared to your hardware controllers and true software raid.
It is critically important to know the difference.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
But this is critical to know the difference. Raid that is provided by some utility that is baked into the motherboard is predominantly more risky than the other options you have. (software and hardware).
Correct. I agree.
@dustinb3403 said in Discovering FakeRAID in the Real World:
Because the utility is way under developed (and used) compared to your hardware controllers and true software raid.
Yeah.
@dustinb3403 said in Discovering FakeRAID in the Real World:
It is critically important to know the difference.
I have always known the difference. This was never about me not knowing the difference between hardware/software/fake RAID.
Regardless of what kind of RAID it is, you get it with your motherboard. That's what this was always about.
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@obsolesce said in Discovering FakeRAID in the Real World:
Yes, it is end of discussion... What I am getting is RAID, fakeRAID or not, it's still RAID.
And? That very clearly has nothing to do with the discussion which was that you believed your RAID was coming from the hardware, not from software like we said.
So it's not even related to the discussion. If you believe this ends the discussion, I believe it concedes the point that you were confused and never knew what we had been talking about. Because it's very clear that it's not even related.
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Ive used this for desktops before at home, but not with a server.
Sometimes there is an issue with the os seeing these onmobo raid devices as a single device.
For example, if you setup a raid1 through mobo raid, then load a Centos iso and attempt to install to your raid 1 device, you will likely find that the raid1 device isn't seen by the installer, and you will still see two hdd to choose for installation. Another thing you can run into is the raid device will be available during installation showing as a single device, you install to it, reboot, and then get No Operating System found error after POST. -
@bnrstnr said in Discovering FakeRAID in the Real World:
Please explain to us how the disks get in a redundant array if not from the motherboard.
Software RAID does this. It did it before there was hardware RAID at all. Hardware RAID is the more recent type. Old, but more recent.
It's hard to know what needs to be explained, I'm not sure why you feel hardware is needed. But I'll attempt...
RAID is simply a form of drive interface abstraction, but that does certain things beyond the abstraction. So it is most similar to Logical Volume Management. LVM does not do RAID, but they both abstract in a similar way, consuming drives, presenting drives.
RAID is always in software, even when it is on dedicated hardware. So anything that a hardware RAID card can do, you can do without it as well. But people want hardware RAID for various reasons - easier moves, offloading CPU work, more RAM, special features from the implementation, ease of use, etc.
RAID in pure software is a part of every operating system in production use for the last few decades (Netware was the last one without it.) Windows NT had it in 1996 if not earlier. Linux by around the same era. AIX, Solaris, HP-UX, etc. all before Windows.
In fact, outside of the Windows world, hardware RAID is unheard of. NAS and SAN of all sizes do it in software. All big iron servers do it only in software. It is hardware that is the niche, not the norm.
So what happens is that you have a software driver on your OS (integrated or third party, doesn't matter) that grabs the drives, does it's RAID magic, and then presents it on to the storage subsystems above it as a single drive. It's not actually very complicated once you see it in action, it's pretty basic. Very simple code if just doing say RAID 0 or 1. That's what makes those so reliable, it's just so simple.
Then the storage above the RAID layer sees a single, new drive. The one made by the RAID system. And it treats that like the attached hardware and acts normally.
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@momurda said in Discovering FakeRAID in the Real World:
Sometimes there is an issue with the os seeing these onmobo raid devices as a single device.
Pretty common. And that is proof that it is FakeRAID in those cases. If the motherboard, or any hardware, was doing the RAID, this would be impossible.
If you can ever induce this scenario, it is proof of software RAID being used.
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@bnrstnr said in Discovering FakeRAID in the Real World:
I've done this, too, on a home computer. The RAID comes from somewhere, and it's nothing added by any other component other than the motherboard. It's not windows that does it, it's not the RAM, it's not the power supply... it comes from the motherboard, somehow.
This is where the FakeRAID comes in. And we talked about this higher in the thread. It does come from somewhere else, it comes from drivers that you add. It's easy enough if you have a real world example, to demonstrate it happening. It's running on the OS, in every case. It's always the same. What you are describing is exactly what @Obsolesce is, and it's exactly what we said to expect when looking at FakeRAID.
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@obsolesce said in Discovering FakeRAID in the Real World:
@scottalanmiller said in IDE Raid- Is there a Benefit?:
Which is worth pointing out that 99.99% of motherboards don't have RAID, on desktops. And 98% don't have it on servers.
This is what I'm debating, this "fact" here. Not about the type of RAID.
Is it? Because you didn't provide anything to suggest that this was wrong, only repeated the information we told you you would get. So you basically repeated us back.
Then you claimed that you only cared if you got RAID, not where it came from and said, based on that, that the discussion was over.
You also said you didn't care if it was hardware or not. But now you say you are only caring if it is hardware.
You are flip flopping trying to make a point, but the point isn't clear. You didn't like the assertion that most motherboards don't have RAID (or that they all lie about it.) But you've provided nothing to the contrary. Lots of arguing, but no counter points.
It's like you missed everything we said, and are just continuing to restate what we said you'd see, but stating it as if we didn't expect you to see that, or that we didn't tell you ahead of time that you would.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
The utility you've used on this board is controlled from the Motherboard, thus it's FakeRAID. It "does" RAID but it's such a bad idea to use it that you'd be better off adding a third disk and using proper SoftwareRAID for wherever you want your data to reside.
This isn't clear. There is nothing that operates "on the motherboard" with FakeRAID, nothing at all. It's Fake in that there is no hardware doing the RAID, but is presented as being such. It has nothing to do with being industry standard, and certainly doesn't run on the motherboard, that would require a separate processor, and in doing so, they'd not bother to fake it.
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@bnrstnr said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
So it DOES come from the motherboard?
No, he's confused. It absolutely does not.
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@dustinb3403 said in Discovering FakeRAID in the Real World:
@bnrstnr said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
So it DOES come from the motherboard?
It has too, there is no where else for it to reside and run.
This is completely incorrect. Not only does it not have to, it cannot. There is no hardware on the board to do it, and we can trivially (and have so many times) proven that it is not. You cannot bypass the RAID if this were true, but you always can.
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@obsolesce said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
Are you getting the FakeRAID from the powersupply? No. From the motherboard? Yes.
So yes, 99% of motherboards DO have raid (even if it's FakeRAID, it's still RAID). This was my original point.
They absolutely do NOT have RAID. That is wrong. Find any board you like as an example and we can demonstrate it. This is trivial to show in the real world. There is no reason to use hypotheticals.
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@obsolesce said in Discovering FakeRAID in the Real World:
If you go back and read my posts, you'll see the type of RAID was never part of my point. That was what Scott was saying was my point, confusing everyone else including himself.
You said you didn't care where it came from, I'll go find the quote.
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@obsolesce said in Discovering FakeRAID in the Real World:
I don't care about hardware RAID, software RAID, or fakeRAID.
Right here. You said you didn't care if it came FROM the motherboard or not. You were just trying to say you got RAID in the end.
Now you are stating the opposite.
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@scottalanmiller said in Discovering FakeRAID in the Real World:
@bnrstnr said in Discovering FakeRAID in the Real World:
@dustinb3403 said in Discovering FakeRAID in the Real World:
It's not hardware raid. It's a piece of code that is operated within your motherboard (and by the CPU on your board).
So it DOES come from the motherboard?
No, he's confused. It absolutely does not.
How does it not?
If you remove the motherboard, you lose the RAID. The whole thing comes from the motherboard. The motherboard provides the fakeRAID, it's built into the motherboard. The RAID exists without the OS. You can confirm the RAID is there by hitting CTRL+R or whatever it is, and seeing that the RAID1 is there, active, working.
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@scottalanmiller said in Discovering FakeRAID in the Real World:
@obsolesce said in Discovering FakeRAID in the Real World:
I don't care about hardware RAID, software RAID, or fakeRAID.
Right here. You said you didn't care if it came FROM the motherboard or not. You were just trying to say you got RAID in the end.
Now you are stating the opposite.
No, I said I don't care what type the RAID is...
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Scott, something has to process to "fakeRAID" components during the setup phase. The CPU is what is doing this. Not a dedicated CPU.
It is still FakeRAID, because (and in the above example) of seeing multiple disks once you go to install do you prove that the FakeRAID is actually fake.
The "run this raid program via CTRL + <something>" can't be run without some RAM and CPU. It's still Fake, but it is being run by the CPU on the motherboard.
It's still fake 100% though.
