Limitations not applied inside of containers

First, thanks for quick reply.

You mean about these:

lxc.cgroup2.cpuset.cpus = 0-3
lxc.cgroup2.memory.soft_limit_in_bytes = 4294967296
lxc.cgroup2.memory.limit_in_bytes = 4294967296

With these parameters the container can’t start:

WARN     cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits_legacy:2852 - Invalid argument - Ignoring legacy cgroup limits on pure cgroup2 system
ERROR    cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:2951 - No such file or directory - Failed to set "memory.soft_limit_in_bytes" to "4294967296"

Any idea?

Edit: this is what I see in the “old” (Debian 10) systems:

# mount | grep cgroup
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/rdma type cgroup (rw,nosuid,nodev,noexec,relatime,rdma)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,clone_children)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)

and this is the output on Debian 11:

# mount | grep cgroup
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime)

Edit2: also note, that I can set the limit to CPU’s with this command:

lxc-cgroup -n mycontainer cpuset.cpus 0-3

But only the CPU’s, and only after the container has started.