container I/O separation

For lxc:

lsblk to get device:

└─sda3 8:3 0 3.7T 0 part
├─pve-root 251:0 0 10G 0 lvm /
├─pve-swap 251:1 0 2G 0 lvm [SWAP]
├─pve-data_tmeta 251:2 0 116M 0 lvm
│ └─pve-data-tpool 251:4 0 3.6T 0 lvm
│ ├─pve-data 251:5 0 3.6T 0 lvm
│ ├─pve-dir 251:6 0 50G 0 lvm
│ ├─pve-vm--60200--disk--1 251:7 0 600G 0 lvm

then
limit read to 10KB/s for container 60200
echo "251:7 10000" > /sys/fs/cgroup/blkio/lxc/60200/blkio.throttle.read_bps_device

for iops use blkio.throttle.read_iops_device

REF: https://forum.proxmox.com/threads/i-o-disk-limit.28591/