Hi, I am testing Unraid and want to partition the cache drive, so the 1TB ssd could also be used in VM's for temp directories and as a bcache but every time I partition the drive with fdisk I get "Unmountable: Unsupported partition layout".

Any ideas why?

2 minutes ago, silajim said:

Any ideas why?

It's not possible, Unraid requires one partition using the entire device, it might work if you change to a pool, and you can have a single device pool, just need pool slots set to >1, pools require btrfs.

Also note that if it works it's not supported, and it might stop working in a future release.

Just gave it a try and it does not work, maybe I can create a vhd on the cache drive and mount that to use as bcache 

2 hours ago, silajim said:

create a vhd on the cache drive and mount that to use as bcache 

Unraid will not use vhd for any of the usual user share functionality and Unassigned Devices won't mount it for you either. You would be pretty much on your own at the command line if you pursue this.

 

I don't really see the need anyway. You can just have a cache drive and use it for whatever purpose you want, caching user shares, fast storage for dockers/VMs, whatever. Just setup different user shares for different purposes, and configure each to use cache as appropriate for your use.

 

That is what most have always done until multiple pools were introduced for 6.9+

I allready have a "working" sample in a vm. I created a new VM (yes inside the unraid vm) with a secondary image file that resides in a cache only share. But I didn't use Bcache but FS-cache but I cannot speak for performance yet

6 minutes ago, silajim said:

inside the unraid vm

Running Unraid in a VM isn't supported, but there is a subforum here for users to help each other with that.

I know, it's just for testing purposes