QCOW vs LVM for KVM storage pools
I'm building an Ansible role for setting up KVM hypervisors, and it lets users configure storage pools in three ways: qcow2 (dir pool), LVM, and LVM-thin.
A colleague argues that qcow2 is slow and unfit for production, and that we should only support LVM.
My take is that it's not really qcow2 vs LVM, it's which backend fits which workload. qcow2 gives you easier snapshots and backups, better Cockpit support, and portability since images are just files. LVM wins on raw I/O for heavy workloads like databases, but you lose file-level convenience and most backup/restore work moves to the command line.
Is qcow2 genuinely a problem in production these days, or is that reputation left over from older qemu? Curious what people are actually running these days?