[ovirt-users] Re: mdadm vs. JBOD

On Thu, Jan 20, 2022 at 8:52 AM <jonas(a)rabe.ch&gt; wrote: Hello, I somehow missed your original email. While I don't have a comparable setup (We usually opt for mixed SSD HDD setups with fast VMs running on SSD bached gluster volumes and large-storage VMs using HDD backed gluster volume), I can offer some insight. 1. Performance wise, using software RAID10 on the NVME drives will give you great performance, while reducing the chance of a double drop. 2. Avoid using RAID5/50/6/60 as the write amplification will eat up your read-intensive NVMEs life span in a couple of months. 3, Use a fast network back-end. A good high-end server with hardware RAID HDD can easily saturate a 10GbR Linux @peak load. 4. Use arbiter volumes, split the load between the nodes to reduce the write amplifications. (N1: brick, brick, arbiter. N2: brick, arbiter, brick. N3: arbiter, brick, brick). 5. In general I usually avoid using the wizard, manually creating the gluster volumes before I begin the deployment. - Gilboa