Any benefits to adding a spare M.2 SSD

[Robbbbo666]

I have recently setup my hex os nas and my mobile has 2 m.2 slots

currently both are populated with 256GB drives as I had a heap from old machines.  I set it up so there is a redundant boot on the second drive.

Is there a better way to set it up?  

Can it be used as cache?

I have a spare 1TB drive, that any better?

I saw somewhere about potentially using an m.2 to hold Plex thumbnails etc to make it snappier than from reading it direct from the HDD array, is that a use case?  If so how do I go about it?

 

Specs: AMD 5700G with 16gb 2666mhz ram on an ITX B550 board

[PsychoWards]

Hey, 

I would (and am) using the 2nd slot for a redundant boot drive.

There is no write cache in Hexos, so no way to increase write performance.

There is a read only cache called L2ARC and as you mentioned you can offload some metadata to the drive:

 

There is no "best use case", because it really depends on the own needs and what is the most important to you.

You might not even notice the benefits of using an SSD to store metadata, or your primary boot SSD might never die. It's a matter of reading into the different options and make an education decision based on what's important for you and what isn't. 🙂 

[Robbbbo666]

Thanks!

I'll look into the link you posted and set that up.

The redundancy I don't think is important in my use case but I will do some digging and see what I require and decide from there

i may even be able to get a 3rd drive into the PCIe slot as a L2ARC drive for the time being so I can test how the boot drive is going/see the benefits of using a m.2 for meta data

[PsychoWards]

If you are adding an L2ARC, the general rule of thump is that it should be 10x your RAM.

So. If you only have 16GB of RAM don't put a 1TB SSD as L2ARC, because the L2ARC also puts strain on your memory and putting to much of it hurts the system in the end. 

Also L2ARC and Metadata SSD might be redundant, if the metadata is stored in the L2ARC, there is no point in having the SSD and vis versa but this depends a lot on the hitrate of your ARC.