How can I partition my M.2 SSD with 32GB Optane Memory AND 512GB SSD for use as both a boot drive and cache?

[Azaz]

So I got this M.2 SSD to use as a Boot Drive and a Cache hopefully. The listing showed "Optane Memory 32GB + SSD 512GB", so I was hoping that I could try and partition the drive to install the boot on one half of the SSD and then use the 32GB of Optane Memory as a Cache. I hope that makes sense so far?

The problem is that I'm struggling to determine how to partition the SSD to allow that—specifically, making sure I partition the right parts of it technically. I don't even know where to start. Heck, that might not even be what I need. I'm not sure. I really don't want to have to wait for another SSD to arrive, but I fear that I might need to order a 2nd SSD nonetheless...

I'm sorry in advance for any ineptitude on my part, I am only just now getting into TrueNas Core and Linux for that matter, so I might need you to explain it to me like I'm 4! Nonetheless, any help would be greatly appreciated!

Here are the specs of my system

• Motherboard: ASRock B550 Phantom Gaming-ITX/ax
• CPU: AMD Ryzen 5 5600G
• RAM: Crucial 32GB (2 x 16GB) DDR4 3200 CT2K16G4DFRA32A
• SSD: Intel M.2 22 x 80mm Optane Memory 32GB + SSD 512GB PCIe NVMe 3.0 x4 HBRPEKNX0202A01
• HDD: 4x WD Red Pro WD161KFGX 16TB
• Case: JONSBO N1 Mini-ITX NAS Chassis

 

[Azaz]

Correction: Currently running the latest version of TrueNAS SCALE 22.12.0

 

[Arwen]

In general;

I have to waste an entire drive just for booting?

With the advent of TrueNAS Scale, we seem to be getting a large number of people from the Linux community who are not quite grasping what TrueNAS is. TrueNAS is not a "Linux distro" and it is not designed to try to meet your arbitrarily spec'd...

www.truenas.com

Second, some of the Optane M.2 are setup weirdly, using 2 PCIe lanes for the Optane and 2 PCIe lanes for the other more standard SSD, (512GB in your case). AMD processors generally don't support bifurcation of a 4 lane M.2 slot. It's an Intel processor thing. So you would likely need a specialized PCIe card, which I don't know if anyone actually makes.

 

[artlessknave]

you cannot partition the boot drive. the boot drive is only the boot drive, nothing else.
trying to do so is completely unsupported. it is *possible* but it's janky and likely to do weird things or just die.
it's like kicking a puppy. just don't do it.

 

[Davvo]

The paaain. Arwen is right.
You also don't want a strange cache on your drives, it can cause issues (though I think having it on the boot pool exposes you to less risks compared to on the data pools).

 

[joeschmuck]

So I got this M.2 SSD to use as a Boot Drive and a Cache hopefully. The listing showed "Optane Memory 32GB + SSD 512GB", so I was hoping that I could try and partition the drive to install the boot on one half of the SSD and then use the 32GB of Optane Memory as a Cache. I hope that makes sense so far?

It's a great idea but only if the drive exposes itself as two different drives, then you might have a supported way to do it, not if it's a single drive. You have all the other comments above which of course I agree with. Don't kick the puppy.

 

[HoneyBadger]

Second, some of the Optane M.2 are setup weirdly, using 2 PCIe lanes for the Optane and 2 PCIe lanes for the other more standard SSD, (512GB in your case). AMD processors generally don't support bifurcation of a 4 lane M.2 slot. It's an Intel processor thing.

This is exactly the case. The Optane H-series cards require bifurcation support on the M.2 slot, which generally doesn't exist on the AMD platform.

If it does exist though, the device will expose itself as nvd0 and nvd1 as suggested by @joeschmuck - and you can treat the two devices independently without worry of one interfering with the other.

Also note that the "large" portion of the H-series SSDs is QLC NAND, which is best suited to lighter write workloads.

 

[Azaz]

I figured. Thanks to all who helped! Extremely helpful.
And don't worry, I won't kick the puppy.

 

[Azaz]

It's a great idea but only if the drive exposes itself as two different drives, then you might have a supported way to do it, not if it's a single drive. You have all the other comments above which of course I agree with. Don't kick the puppy.

Right. Buying it I thought that it would have exposed itself as two different drives but I guess not ¯\_(ツ)_/¯