There are two options for disk images with KVM:
- IO thread
- io=native
By default, Proxmox uses io=native for all disk images unless the IO thread option is specifically checked for the disk image.
The IO thread option allows each disk image to have its own thread instead of waiting in a queue with everything else. Since disk I/O is no longer waiting due to having its own threads, it does not hold up other tasks or queues related to the VM, which in turn speeds up the VM performance besides providing increased disk performance. The IO thread option is fairly new in Proxmox. There were a few reported instances where the VM was locked up due to this option. So perform plenty of testing before implementing this feature in a production ...
