Possible to build a lean UNRAID without HDDs (SSDs only)?

[Econaut]

Spoiler alert... not really; I already built this system thinking I could do one thing but finding out evidently it's not so straight forward:

 

• Gigabyte Aorus X570 Ultra
• Ryzen APU
• 2x 1TB m.2 SSD
• 2x AMD GPUs (different models)
• Suitable PSU

 

And that's it. No HDD's just a really lean GPU pass-through system is what I was going for with the m.2 in RAID 1 (if I can figure that out). So I was able to load up UNRAID and discovered I can't do anything with VMs without first having an array setup... ok. Added an m.2 as parity and the 2nd m.2 as the first data disk and then did some reading and apparently UNRAID can't work this way because TRIM commands won't be issued and the performance will start hemorrhaging over time.

 

Ok, so I tried adding cache only or data only disks and I cannot do much of anything without a parity drive that seemingly has to be an HDD. As luck would have it... this case and build can't really accommodate a HDD. I can add more storage via PCIe and that's about it (+ one other m.2 on the motherboard). If it were even possible, which I'm sure it's not, adding a mini 2.5 HDD via PCIe sounds pretty dumb (just wasting the bandwidth).

 

My goal here was to have simple GUI-based pass-through configuration which supposedly UNRAID delivers. Am I understanding everything correctly in that what I am trying to do with UNRAID is impossible right now?

 

This no TRIM thing seems like a pretty major limitation that hardware manufacturers should be rolling into the firmware... in my humble opinion. My original plan was to just do a motherboard based RAID 1 with the two m.2 and use it as the sole data drive in UNRAID but the bios is a little screwy and even if I create such a RAID 1 it doesn't seem to go live. Even so, seems like that's a non-starter with UNRAID anyways.

 

I do plan on eventually making an actual HDD storage UNRAID someday but that's a major investment I can't make at this time. This recent build was just a replacement motherboard and some m.2s.

Edited March 3, 2021 by Econaut

[SimonF]

You could use a small usb flash drive for array drive if you are not going to use it

Edited March 3, 2021 by SimonF

[Econaut]

Oh good tip, yeah I wouldn't be making use of it if it's just flash drives. I would be able to add a few flash drives.

Would that let me use the two m.2 modules as a single redundant block for VMs?

Edited March 3, 2021 by Econaut

[SimonF]

Yes as you just need a single drive to start the array and set your m.2s as cache

Edited March 3, 2021 by SimonF

[Econaut]

Alright so just one flash drive as the parity drive and no data drives needed?

 

Forgive my naivety but with the m.2's assigned as cache, does that provide persistent VM storage? Can I merge them into a single redundant cache block? (assuming I would have to get the motherboard RAID 1 working for a redundant cache block)

 

In essence, I am hoping to run two GPU pass-through systems (and probably some other headless container/VMs) from this one system.

[itimpi]

3 minutes ago, Econaut said:

Alright so just one flash drive as the parity drive and no data drives needed?

No, one flash drive as a data drive and no parity drive.    You have to have at least one data drive for unRaid to be able to start up the services and pools.

[SimonF]

As itimpi said 1 x flash no parity 2xm.2 in btrfs cache pool will provide 1tb pool for vms and contaimers

[Econaut]

Ok cool. And the data flash drive can be any size? I certainly don't have a 1TB to match (16GB & 32GB)

 

So does the cache pool work in parallel (if 2x 1TB m.2 = 1TB cache pool it's basically a raid1 in that case?) Sorry I cannot yet think in terms of btrfs 😄

Edited March 3, 2021 by Econaut

[trurl]

44 minutes ago, Econaut said:

2x 1TB m.2 = 1TB cache pool it's basically a raid0

That is raid1 and is the default.

[Econaut]

Oops my mistake - I did mean RAID1 (RAID1 is parallel RAID0 is serial, more or less) - edited original.

[Econaut]

10 hours ago, itimpi said:

No, one flash drive as a data drive and no parity drive.    You have to have at least one data drive for unRaid to be able to start up the services and pools.

 

So this is what I have and it is not allowing me to start the array:

 

 

The USB drive in the Disk 1 slot is sdb but is the same model of the boot device.

 

Edit: Seems UNRAID does not like that I am using two of the same drive. Trial is being disabled when I plug the second one in. Got passed that by unplugging data disk, reloading page, starting array, plugging drive back in, formatting, etc. Since the GUI remembered the sdb selection for Disk 1, it thought it had a disk to start with (even though it was unplugged) so that was lucky but it seems to be working now.

Edited March 4, 2021 by Econaut

[SimonF]

Glad you got it working, but did you have UNRAID as a the VOLUME name on second USB that may be why you had a issue re trial Key. Its been formatted now so volume name will be different.

[Econaut]

Yes the secondary USB drive was also named UNRAID. Good to know!

[Econaut]

On 3/3/2021 at 6:28 PM, trurl said:

That is raid1 and is the default.

So to be clear, this cache pool is actually protected similarly to a RAID 1? If one m.2 dies for example, would I be able to replace it and retain all the data that was in the cache pool?

[trurl]

9 hours ago, Econaut said:

So to be clear, this cache pool is actually protected similarly to a RAID 1? If one m.2 dies for example, would I be able to replace it and retain all the data that was in the cache pool?

https://wiki.unraid.net/UnRAID_6/Storage_Management#Replace_a_disk_in_a_cache_pool