Package: libvirtd
Version: libvirt-daemon-system
Severity: normal
Dear Maintainer,
This is on a fresh installation of debian stretch (9.3.0).
I use libvirt Resource Partitioning [1] [2]. The cgroup is created with
systemd:
root@debian9:~# cat /etc/systemd/system/machine-jonas.slice
[Unit]
Description=Slice: jonas
Before=slices.target
Wants=machine.slice
[Slice]
CPUShares=1024
MemoryLimit=9.5G
root@debian9:~# stat /sys/fs/cgroup/cpu/machine.slice/machine-jonas.slice/
File: /sys/fs/cgroup/cpu/machine.slice/machine-jonas.slice/
[…]
When creating a domain with the following XML (using that resource
partition/cgroup according to [2]):
root@debian9:~# cat test.xml
<domain type='qemu'>
<name>test</name>
<memory unit='KiB'>524288</memory>
<currentMemory unit='KiB'>524288</currentMemory>
<vcpu placement='static'>8</vcpu>
<resource>
<partition>/machine/jonas</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-i440fx-2.1'>hvm</type>
<bios useserial='yes'/>
</os>
<features>
<acpi/>
<apic/>
</features>
<cpu mode='host-model'>
<model fallback='allow'/>
</cpu>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<pm>
<suspend-to-mem enabled='yes'/>
<suspend-to-disk enabled='yes'/>
</pm>
<devices>
<emulator>/usr/bin/qemu-system-x86_64</emulator>
<serial type='pty'>
<target port='0'/>
<alias name='serial0'/>
</serial>
<console type='pty'>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
</devices>
</domain>
root@debian9:~# virsh define test.xml
Domain test defined from test.xml
Attempting to start the domain fails with:
root@debian9:~# virsh start test
error: Failed to start domain test
error: Failed to create controller cpu for group: No such file or directory
I attached strace to the libvirtd process to find out which cgroup path
it tries to use:
root@debian9:~# strace -ffp $(pidof libvirtd) 2>&1 | grep cpu
[pid 10876] lstat("/sys/fs/cgroup/cpu", {st_mode=S_IFLNK|0777, st_size=11,
...}) = 0
[pid 10876] lstat("/sys/fs/cgroup/cpuacct", {st_mode=S_IFLNK|0777, st_size=11,
...}) = 0
[pid 10876] lstat("/sys/fs/cgroup/cpu", {st_mode=S_IFLNK|0777, st_size=11,
...}) = 0
[pid 10876] lstat("/sys/fs/cgroup/cpuacct", {st_mode=S_IFLNK|0777, st_size=11,
...}) = 0
[pid 10876] access("/sys/fs/cgroup/cpu,cpuacct/machine/jonas.partition/", F_OK)
= -1 ENOENT (No such file or directory)
[pid 10876] open("/sys/fs/cgroup/cpu,cpuacct/machine/jonas.partition/",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or
directory)
[pid 10876] open("/sys/fs/cgroup/cpu,cpuacct/machine/jonas.partition/",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or
directory)
[pid 10876] open("/sys/fs/cgroup/cpuset/machine/jonas.partition/",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or
directory)
[pid 10876] sendto(8, {{len=192, type=0x9c5 /* NLMSG_??? */,
flags=NLM_F_REQUEST|NLM_F_ACK, seq=42, pid=0}, "virt=qemu resrc=vcpu
reason=star"...}, 192, 0, {sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000},
12) = 192
It tries to use the ``/machine/jonas.partition`` path, which is,
according to [2], only used on non-systemd systems. It appears that
libvirt does not recognize the system as systemd-based, making the start
of the domain fail. Removing the <resource/> section from the domain
config makes the domain start.
I would expect that libvirt recognizes the system such that operation
according to [2] (with a machine-foo.slice file, a
<partition>/machine/foo</partition> should work) is possible.
kind regards,
Jonas
[1]: https://libvirt.org/formatdomain.html#resPartition
[2]: https://libvirt.org/cgroups.html#customPartiton
-- System Information:
Debian Release: 9.3
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.9.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8),
LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
