Possible to add (part of) cache disk to array for VMs?

[technologiq]

I apologize if this is a stupid question but I have 7 drives in my Unraid Server, one of them is a 512GB SSD (Samsung 860 pro).  This has always just been my cache disk but I would like to take advantage of that drives speed for my VMs.   I know I could just put the VMs on that drive, but the drive would not be part of the array.  Is there any way to get the VMs on this into the array?  I know I could set up some kind of script to copy the VMs daily but that could be intense with large vdisks.

 

Thank you!

[Jcloud]

I'd just keep your Samsung 860 as your cache, and when you make a VM, in the webui, it should default to the path:  /mnt/cache/domains/NameOfYourVM/vdisk1.img

 

In general you don't want a virtual machine's disk image on the array, because it's too slow.  The reason the array is too slow is because of the Parity over-head. And, afaik you can't allocate part of a cache drive to be part of the disk array (directly answering question of subject-line).

 

The two useful configurations seems to be: image file on your cache drive (mover isn't going to touch it), or pass-through an entire drive which the VM installs onto.  Either way, you're right you're not on the disk array, but you could make a snapshot-copy of the vdisk1.img file. Also, see a lot of people map a user share inside the VM, and that gets used for user data so that gets array benefits. 

 

My two cents, I hope that helps.