Questions tagged [cgroup]
cgroups (control groups) is a Linux kernel feature to limit, account and isolate resource usage (CPU, memory, disk I/O, etc.) of process groups.
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How does systemd put sshd processes in slices?
I'm diagnosing an SSH bastion I manage. This machine has about 5500 SSH connections with port forwarding at any given point in time.
Recently, I ran into an issue where SSH connections where refused ...
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Kill a running process inside a docker
I've run a find command on a very large folder inside my docker, and now it is stuck for more than an hour.
I've tried to kill -9 the process, and kill the docker container with docker kill <...
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1answer
38 views
User sessions under the systemd control group hierarchy, why it's needed?
When a user log in a server with systemd, the PAM logic execute pam_systemd.
With that module, the users are registered under the systemd control group. This is an example of two users (root and a ...
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1answer
44 views
How to restrict access to GPU?
I'm configuring a small GPU server under Ubuntu 18.04.
It should support both interactive and batch jobs.
It is dedicated to run machine learning tasks by a small team. We have also some tasks for ...
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51 views
systemd-logind: Failed to create cgroup … No such file or directory
Getting the error below in auth.log. Had a similar issue with sshd and systemd before however but I think this is unrelated. cgroup is involved somehow. Any thoughts? This host is running as a Proxmox ...
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1answer
79 views
Is it possible to get the cgroup path for a Docker container managed by Kubernetes?
When we use kubectl describe pods <pod_name>, a great deal of information is output, including the node that the server is running on, and miscellaneous information about the pod, including the ...
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User Resource management: cgroups + systemd + ssh
I am trying to limit the memory of a single user that keeps crashing our OpenSuse Server.
What I have done is as desribed here, to modify the limit of the user's slice via
systemctl set-property ...
1
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1answer
54 views
What's the recommended way to deal with controled processes if CGroups fails?
I've been using the service unit bellow to start a couple of process that happens to have a high CPU and disk bandwidth usage when running.
Since the processes I want to limit don't have a way to ...
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1answer
558 views
List of controllers empty with cgroup v2
I am trying to learn how cgroups v2 work. I did this:
mount -t cgroup2 none /mnt/cgroup2
That gave me a list of objects in /mnt/cgroup2
root@ubuntu-s-1vcpu-1gb-lon1-01:~# ls -la /mnt/cgroup2/
total ...
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1answer
75 views
Stack trace of mount command shows File not found error
When I run a program, I am getting a mount error:
[root@host ~]# ip vrf exec wan1 /usr/sbin/ssh root@1.2.3.4
Failed to mount cgroup2: No such file or directory
I know my kernel supports cgroup2:
[...
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0answers
106 views
`systemctl show` outputs incorrect MemoryCurrent value
on one box, systemctl show get an incorrect value for unit memory usage:
$ systemctl show crond | grep MemoryCurrent
MemoryCurrent=18446744073709551615
18446744073709551615 == UINT64_MAX, this must ...
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2answers
106 views
systemd deletes sub-cgroups started by other services
I have a service (HTCondor batch system), which is started as service unit within cpu,cpuacct and memory cgroup slices (CentOS 7 @ 3.10.0-*).
The service starts sub-processes (~~> batch jobs) for ...
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1answer
266 views
Docker swap support in ubuntu 18.04
It seems like Ubuntu 18.04 broke docker swap support.
It's working fine in ubuntu 16.04, but this morning when I setup a new server with ubuntu 18.04 it didn't work.
Does anyone know how to enable ...
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1answer
526 views
Page cache usage listed in cgroup's memory.stat file
A cgroup's memory.stat file lists the page cache usage for that cgroup (in cache and total_cache fields). How is the page cache usage derived?
For example, file a.txt is opened by both cgroup A and B....
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1answer
2k views
The memory usage reported in cgroup differs from the free command
Why would the free command be reporting a much different mem usage number vs cgroup?
$ free -b
total used free shared buff/cache available
Mem: 2096914432 ...
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1answer
3k views
Kubernetes cgroup driver misconfiguration
Default Docker installation in CentOS starts with systemd Cgroup. I installed Kubernetes from official YUM repo and systemd drop-in 10-kubeadm.conf has the following contents:
[Service]
Environment="...
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0answers
802 views
Why do user and system cpu in cpuacct.stat not add up to cpuacct.usage?
Question relates to Linux cgroups cpu accounting.
I noticed this at the container level, but it persists up to top level. For instance:
# cat /sys/fs/cgroup/cpu/cpuacct.stat /sys/fs/cgroup/cpu/...
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1answer
328 views
Cannot move all processes by a user into cgroup using cgred
I am on a CentOS 7.4 server, and trying to setup CGroups.
My cgconfig looks like this:
#
# Copyright IBM Corporation. 2007
#
# Authors: Balbir Singh <balbir@linux.vnet.ibm.com>
# This ...
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votes
2answers
2k views
How do I set cgroup limits for systemd user slices?
I would like to limit usage of a system on a per user basis. Since Systemd has native support for cgroups, I think using user slices is the way to go.
The problem is: I can't figure out how to set ...
2
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2answers
517 views
How to detect if a process was killed by cgroup due to exceeding a limit?
I have a global cgroup defined in /etc/cgconfig.conf that limits the amount of memory. Everytime a user runs a command, I prepend cgexec to add the process and its children to the controlled group. ...
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1answer
929 views
CGroup configuration in CentOS 7
I am using CentOS 7 and I have several users registered in system (UIDs: 1000, 1001, 1002, etc)
I want to restrict memory consumption for each user using cgroup and systemd.
The following commands ...
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1answer
308 views
Centos7 cgroups, limit cpu shares for cronjobs
Is it possible to limit the cpu shares for processes started from cron? Background: We have shared hosting on Centos7 and customers can make cronjobs via directadmin controlpanel. Sometimes these ...
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0answers
709 views
Use of cores with `isolcpus` and `cpuset`
I have a Red Hat Enterprise Linux Server release 6.9 (Santiago) (I don't manage it). In the GRUB config file I have, let's say, isolcpus=2-32 (out of 36 cores). I also have a cgroup with cpuset=2-32 ...
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198 views
Enable cgroups on Beowulf compute nodes
We are running a Beowulf cluster using the Scyld distribution from Penguin Computing, and it looks like cgroups are configured on the head node, but not the compute nodes. I'm trying to configure ...
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cgconfig daemon restart leaves threads in root cgroup
I'd like to ask if my explanation of the behavior I observe is correct.
The behavior: After restarting cgconfig daemon, the processes have correct core affinity (as verified by taskset) but the ...
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0answers
91 views
cgroup throttle on child device does not work
We're running Docker containers with devicemapper on CentOS 7 (3.10.0-514.10.2.el7.x86_64).
For some containers we can easily throttle reads through blkio.throttle.read_bps_device by specifying the ...
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0answers
110 views
How do I audit cgroup changes
I have a container process that is mysteriously changing cgroups long after it has been started. How do I track down who/what is changing it? I tried watching my audit log when manually doing a ...
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1answer
749 views
I can't get the cgroup blkio to throttle the iops of processes in a sub-cgroup
I can't get the cgroup blkio to throttle the iops of processes in a sub-cgroup. I am using CentOS 7, 3.10.0-229. I create the cgroup /sys/fs/cgroup/blkio/user.slice/test1 and do
echo 8:32 10 > /...
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1answer
464 views
Host mountpoint inside docker volume inconsistency
I have a simple setup, where I bind-mount a host's folder in a container.
docker run --rm -it -v /mnt:/mnt ubuntu:16.04 bash
Then I mount some other file systems to the host's folder. Mount points ...
3
votes
1answer
369 views
Where is my container's memory going?
I have a container leaking memory. Or at least, reported memory consumption goes up fast. If I run top, I get this:
top - 16:56:51 up 6 days, 17:25, 0 users, load average: 0.16, 0.27, 0.31
Tasks: ...
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0answers
272 views
cgexec not inheriting LD_LIBRARY_PATH
My /etc/cgconfig.conf file consists of
mount {
cpuset = /cgroup/cpuset;
cpu = /cgroup/cpu;
cpuacct = /cgroup/cpuacct;
memory = /cgroup/memory;
devices = /...
2
votes
1answer
507 views
Is there a way to set the cgroup that systemd launches a process in?
systemd launches a process in the /system.slice/process-name.service cgroup. I would like to launch the process in a different cgroup. I can do this using cgexec in the ExecStart option, but is there ...
2
votes
1answer
142 views
Why LXC requires restart?
LXC documentation says:
Just before you create your first container, you probably should logout and login again,
or even reboot your machine to make sure that your user is placed in the right ...
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1answer
1k views
How do I set the default memory.swappiness for all the systemd cgroups?
In CentOS 7 how do I set the default memory.swappiness for all the systemd cgroups? I can do it per cgroup via the ControlGroupAttribute option, but I would like to override the default of 60 for all ...
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0answers
608 views
How to view cgroups resource control heritage between parents and childs process
Taking for example this hierarchy from systemd-cgls:
└─user.slice
├─user-1000.slice
│ ├─user@1000.service
│ │ └─init.scope
│ │ ├─3262 /lib/systemd/systemd --user
│ │ └─3263 (sd-pam)
...
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0answers
125 views
Replacing net_cls with nftables
I am currently using the net_cls cgroup to classify packets from a process and then later mangle them with iptables. From the kernel and systemd guys it seems that net_cls is deprecated and other ...
3
votes
1answer
2k views
Freeze and unfreeze processes transparently?
I'm looking for a way to transparently freeze (pause) a process and then unfreeze it later. This is possible with SIGSTOP, but SIGSTOP causes the parent to be notified (by returning from waitpid), ...
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votes
0answers
172 views
Can cgclassify be used with systemd based resource management?
So as of redhat/centos 7, system resource management got a big overhaul. Before redhat/centos 7, cgroups were run using libcgroup packages and daemons like cgred.
Before, if I wanted to move a ...
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votes
0answers
286 views
How to trigger initial login so user slice gets created
I may be taking the wrong approach here, but the new centos 7 implementation of cgroups lets you put limits on user's access to system resources by attaching said limits to their slices.
Ie.
...
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1answer
1k views
Can't enable cgroups memory controller
I have Debian 8.5 on DigitalOcean with a kernel version 3.16.7-ckt25-2
I'm trying to enable cgroups memory controller for Docker. I add cgroup_enable=memory swapaccount=1 to ...
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votes
1answer
71 views
cgroup same process with different resources
I have a Jboss application server installed through source and running multiple instances(say 3) of JBoss as a same user in a single machine on different ports.
Using cgroups, I'm trying to do ...
10
votes
1answer
3k views
How does CPU affinity interact with cgroups in Linux?
I'm trying to run multi-threaded benchmarks on a set of isolated CPUs. To cut a long story short, I initially tried with isolcpus and taskset, but hit problems. Now I'm playing with cgroups/csets.
I ...
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1answer
111 views
iptables is marking packets with wrong number while copying file by scp
[Case1] When copying file from server (being on client) to client, packets are marked incorrect with 3 (root).
[Case2] When copying file from server (being on server) to client, packets are marked ...
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0answers
41 views
Limiting Oracle instances resources with Cgroups?
Is it possible to limit the amount of resources (I/O, CPU and Memory) a Oracle instance can consume using only cgroups? (no containers or virtualization)
The reason I wanna do that is because I want ...
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vote
2answers
772 views
Will Linux/Ubuntu running in an LXC container understand cgroup memory limits?
I'm planning to rent a physical server and run MySQL inside an LXC container on that server. I'd like to control maximum memory usage for the MySQL instance using cgroup limits :
lxc.cgroup.memory....
3
votes
1answer
3k views
CGroups memory limit not working
I am trying to limit memory usage for a LXC container using CGroups, but I can't limit the memory.
# lxc-cgroup -n maxdaniel981 memory.limit_in_bytes 134217728
lxc_container: failed to assign '...
3
votes
2answers
4k views
Centos 6 to Centos 7 cgroups
I'm trying to set up resource limits per user in Centos 7, but I can't find the right commands for the new implementation of cgroups (I did read the documentation but it talks about restricting ...
6
votes
1answer
967 views
htop cgroup column widen
How can I see full length of text CGROUP column in htop? I cannot enlarge it.
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0answers
580 views
cgred / cgrulesengd - does not move new user pid to task file
cgrulesengd can't move pid to task file while running as deamon, if I restart cgrulesengd all pids are moved correctly to task file, but new pid's not.
So, if i log in as hello user, and then run ...
2
votes
1answer
5k views
Cgroups, limit memory per user
Is it possible to limit memory usage per user not per group?
This is my config ...
/etc/cgconfig.conf
mount {
cpu = /cgroup/cpu_and_mem;
cpuacct = /cgroup/cpu_and_mem;
memory = /...
