I had a couple machines where I used OpenVZ and recently, on newer versions of Debian (Jessie), I've been using LXC.
I need a way of giving one container priority on host I/O resources, I could do this on OpenVZ and I find that I can do this with LXD only (which from what I know, only works on Ubuntu) with:
lxc config set my-container limits.disk.priority 10
But as Debian doesn't have LXD, is there a way I can prioritize I/O using LXC in Debian Jessie?
As LXD is just a "frontend" for / to LXC, this is not really a question about LXD.
Actually this is done (in the background) via control groups (cgroups), which is a
Linux kernel feature that limits, accounts for, and isolates the resource usage (CPU, memory, disk I/O, network, etc.) of a collection of processes.
and leveraging the blkio subsystem which
controls and monitors access to I/O on block devices by tasks in cgroups. Writing values to some of these pseudofiles limits access or bandwidth, and reading values from some of these pseudofiles provides information on I/O operations.
should give you your expected results.
There are multiple parameters which are tuneable, for details have a look at the documentation at kernel.org as well. Over here you'll find specific examples related to LXC.
