[TriLUG] kvm host disk swapping dance

[Mauricio Tavares via TriLUG]

So my old and trusty KVM host uses two 240GB SSDS in a raid1
controlled by an Areca card. VM guest disks are logical volumes in the
same volume group as the OS.

But, this is 2019.

So, I was thinking on

1. Create a raid1 just for the OS. On its own drives. It might be a
waste of disk space but SSDs under 512GB are cheap, and under 256 even
cheaper.

2. Create second raid 1 for the vm guests. At least the ones I do not
want to iscsi (give the entire thing to nas)/NFS (just have each vm
guest boot disk locally) off my storage. I have been doing the iscsi
thingie with my esxi box and that has working pretty will without
taxing the nas guy.

Now, my Areca card still works fine and never let me down, but would I
be better served with software raid, perhaps even zfs? Reason is the
card can only handle 4 drives and my case has enough bays for 8 drives
if I really want to (which I might if I decide to make it become a
storage thingie and get a new computer for the job of vm host). And
that means I can upgrade raids and raid thingies.

Thoughts?