Considering Unraid for a new server. It's got 4 SSD's and 5 HDD's.

 

The SSD's are meant for VM's and Docker stuff. Things that really need to be fast. The HDD's are going to be part of the actual fileserver bit of the server.

 

How can I achieve this? I remember that creating multiple arrays wasn't a thing, but it was coming? Maybe?

With or without multiple arrays, how should I set it up in such a way that it behaves the way I described?

Edited October 4, 20223 yr by thany
typo

You can have multiple pools outside the parity array. Cache was the original pool outside the array. Now you can have additional pools, named as you wish. You don't even have to have one named 'cache' if you don't want. A pool can have multiple disks if it uses btrfs raid. Pools, like original cache, are still part of user shares. Each user share has settings that control which pool it uses and how.

 

Many of us do exactly what you want to do, with SSDs in a pool and HDDs in the parity array.

Alright, sounds good! I know the term "pools" a little bit from evaluating TrueNAS with its ZFS filesystem. I'm guessing it works similar on btrfs?

 

Also, what would keep me from not having an array at all, and just create two pools: one with the SSD's and another one with the HDD's? Is this advisable, or even possible?

Edited October 5, 20223 yr by thany
typo

20 minutes ago, thany said:

Also, what would keep me from not having an array at all, and just create two pools: one with the SSD's and another one with the HDD's? Is this advisable, or even possible?

Unraid insists on having at least 1 drive in the main array, but for your Use Case you could make this a small thumb drive which is not intended to store data and have 2 pools with the actual data.