I have a little J1900 CPU server running debian linux with 8GB of ram and a 64GB SSD. I am using it to run a few very lightly loaded kvm virtual machines. It's not a very powerful server but demands are low except i need a lot more disk space. Performance isn't much of an issue but reliability is.
Now, I have an ICY BOX disk enclosure containing 2 4GB hard disks connected to it by USB3. I need some reliability so was thinking I could use ZFS on the two disks and have the mirror so that I get some tolerance to disk failures at the cost of half the disk space. I would then create zfs volumes on the disk for each VM to use as it's storage.
Is this a reasonable way to organize this? I heard that ZFS uses a lot of ram though, will this eat into my limited 8GB a lot?
Or am I better using mdadm for raid1 mirroring of my disks (assuming this works on USB mounted disks) and then LVM to divide up the space?