Description of problem:
On RHEL 8 there is no io.weight interface in cgroups, we only have io.bfq.weight.
The same situation applies to cgroups v1 where we also have only blkio.bfq.weight which was fixed by EngineeringBZ 1657810.
Steps to Reproduce:
1. Boot RHEL-8 machine with systemd.unified_cgroup_hierarchy=1 on the kernel cmdline start with cgroups v2
2. run `systemctl set-property $YOUR_FAVORIT_UNIT IOWeight=123`
3. check if the value is set by running `cat /sys/fs/cgroup/$YOUR_FAVORIT_UNIT/io.bfq.weight`
Fixed in upstream by commit https://github.com/systemd/systemd/commit/2dbc45aea747f25cc1c3848fded2ec0062f96bcf
fix merged to github master branch -> https://github.com/systemd-rhel/rhel-8/pull/178
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (systemd bug fix and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.