From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Friesen Subject: blkio cgroups controller doesn't work with LVM? Date: Wed, 24 Feb 2016 12:12:19 -0600 Message-ID: <56CDF283.9010802@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: dm-devel.ids Hi, Are there known limitations with the blkio cgroup controller when used with LVM? I'm using Ubuntu 15.10 with the 4.2 kernel. I got the same results with CentOS 7. I set up two groups, /sys/fs/cgroup/blkio/test1 and /sys/fs/cgroup/blkio/test2. I set the weight for test1 to 500, and the weight for test2 to 1000. If I then read/write to a file on /dev/sda1 from a process in each group, then everything works as expected and test1 gets half the bandwidth of test2. If I do the same but accessing an LVM logical volume, where the underlying physical volume is /dev/sda4, then both groups get the same bandwidth. It appears that the group weight doesn't get propagated down through all the layers. Am I missing something? If not, is this documented anywhere? Thanks, Chris