[ovirt-users] Hardware critique

I'm spec'ing hardware for a 3-node oVirt build (on somewhat of a budget). I plan to do 20-30 Linux VMs most of them very light weight + a couple of heavier hitting web and DB servers with frequent rsync backups. Some have a lot of small files from large github repos etc. 3X of the following: Dell PowerEdge R720 2x 2.9 GHz 8 Core E5-2690 (SR0L0) 256GB RAM PERC H710 2x10GB Nic Boot/OS will likely be two cheaper small sata/ssd in raid 1. Gluster bricks comprised of 4x2TB WD Gold 7200RPM SATA HDDs in RAID 10 per server. Using a replica 3 setup (and I'm thinking right now with no arbiter for extra redundancy, although I'm not sure what the performance hit may be as a result). Will this allow for two host failure or just one? I've been really struggling with storage choices, it seems very difficult to predict the performance of glusterFS due to the variance in hardware (everyone is using something different). I'm not sure if the performance will be adequate enough for my needs. I will be using an all ready existing Netgear XS716T 10GB switch for Gluster storage network. In addition I plan to build another simple glusterFS storage server that I can use to georeplicate the gluster volume to for DR purposes and use existing hardware to build an independent standby oVirt host that is able to start up a few high priority VMs from the georeplicated glusterFS volume if for some reason the primary oVirt cluster/glusterFS volume ever failed. I would love to hear any advice or critiques on this plan. Thanks!