From lfbm.andamentos at gmail.com  Sat Aug  8 15:20:17 2020
From: lfbm.andamentos at gmail.com (Luis Felipe Marzagao)
Date: Sat, 8 Aug 2020 12:20:17 -0300
Subject: [lxc-users] No swap space inside containers
In-Reply-To: <CAPE6YbTbZsuBaaiQhG9=qCssG4P21TFZoBfbRhQ-PG9tBMhPtA@mail.gmail.com>
References: <CAPE6YbTbZsuBaaiQhG9=qCssG4P21TFZoBfbRhQ-PG9tBMhPtA@mail.gmail.com>
Message-ID: <1dd41003-f5fd-85ee-db7a-43ae6c0d964b@gmail.com>

Swap is ok on the host:

manager at andromeda:~$ sudo swapon --show
NAME       TYPE      SIZE USED PRIO
/dev/zram0 partition   2G 256K    5
/dev/zram1 partition   2G 256K    5
/dev/zram2 partition   2G 256K    5
/dev/zram3 partition   2G   0B    5
/swapfile  file        2G   0B   -2

manager at andromeda:~$ free -h
               total        used        free      shared buff/cache   
available
Mem:            15G         11G        809M         53M 3.0G        3.5G
Swap:          9.8G        768K        9.8G

But there is no swap inside containers:

manager at andromeda:~$ lxc exec pbx -- free -h
               total        used        free      shared buff/cache   
available
Mem:            15G        546M         14G         50M 187M         14G
Swap:            0B          0B          0B

manager at andromeda:~$ lxc exec sombrero -- free -h
               total        used        free      shared buff/cache   
available
Mem:            15G        630M         14G        164K 102M         14G
Swap:            0B          0B          0B

I didn´t change any settings regarding swap or memory. This is a pretty 
standard ubuntu + lxd installation.

manager at andromeda:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.4 LTS"

manager at andromeda:~$ snap list
Name    Version    Rev    Tracking       Publisher   Notes
core    16-2.45.2  9665   latest/stable  canonical✓  core
core18  20200724   1885   latest/stable  canonical✓  base
lxd     4.4        16530  latest/stable  canonical✓  -

Any pointers?

Thanks  a lot.



From cornelis.bos at gmail.com  Sat Aug  8 16:11:01 2020
From: cornelis.bos at gmail.com (Kees Bos)
Date: Sat, 08 Aug 2020 18:11:01 +0200
Subject: [lxc-users] No swap space inside containers
In-Reply-To: <1dd41003-f5fd-85ee-db7a-43ae6c0d964b@gmail.com>
References: <CAPE6YbTbZsuBaaiQhG9=qCssG4P21TFZoBfbRhQ-PG9tBMhPtA@mail.gmail.com>
 <1dd41003-f5fd-85ee-db7a-43ae6c0d964b@gmail.com>
Message-ID: <621babc3cc743e3934ebb60c9beed5c83a3eeeff.camel@gmail.com>

On Sat, 2020-08-08 at 12:20 -0300, Luis Felipe Marzagao wrote:
<snip />
> 
> Any pointers?
> 


https://discuss.linuxcontainers.org/t/invalid-swaptotal-in-proc-meminfo-swaptotal-0/8231/17




From harald.dunkel at aixigo.com  Thu Aug 13 07:02:30 2020
From: harald.dunkel at aixigo.com (Harald Dunkel)
Date: Thu, 13 Aug 2020 09:02:30 +0200
Subject: [lxc-users] ghost services on LXC containers
Message-ID: <c95b75b8-0e54-5d06-a78e-9da3834c12c6@aixigo.com>

Hi folks,

using Debian 10 and lxc 4.0.2 (or 4.0.4) I found ghost services in my
containers. Sample:

# cat /sys/fs/cgroup/unified/system.slice/cron.service/cgroup.procs
50
0

# cat /sys/fs/cgroup/unified/system.slice/dbus.service/cgroup.procs
48
0

# cat /sys/fs/cgroup/unified/system.slice/zabbix-agent.service/cgroup.procs
0
0
0
0
0
0


PID 0 is not valid here, AFAICT. And zabbix-agent isn't even installed
in my container. Its installed on the host only.

Can anybody reproduce this? See also

https://lists.freedesktop.org/archives/systemd-devel/2020-August/044999.html
https://bugs.debian.org/968049


Every insightful comment is highly appreciated
Harri

From harald.dunkel at aixigo.com  Thu Aug 13 10:23:36 2020
From: harald.dunkel at aixigo.com (Harald Dunkel)
Date: Thu, 13 Aug 2020 12:23:36 +0200
Subject: [lxc-users] ghost services on LXC containers
In-Reply-To: <c95b75b8-0e54-5d06-a78e-9da3834c12c6@aixigo.com>
References: <c95b75b8-0e54-5d06-a78e-9da3834c12c6@aixigo.com>
Message-ID: <95e2f232-ce67-80b6-a34a-1529e16679f7@aixigo.com>

On 8/13/20 9:02 AM, Harald Dunkel wrote:
> 
> # cat /sys/fs/cgroup/unified/system.slice/zabbix-agent.service/cgroup.procs
> 0
> 0
> 0
> 0
> 0
> 0
> 
> 
> PID 0 is not valid here, AFAICT. And zabbix-agent isn't even installed
> in my container. Its installed on the host only.
> 

PS:
Lennart Pottering wrote about this:

Is it possible the container and the host run in the very same cgroup
hierarchy?

If that's the case (and it looks like it): this is not
supported. Please file a bug against LXC, it's very clearly broken.

(https://lists.freedesktop.org/archives/systemd-devel/2020-August/045022.html)


I would be highly interested in your thoughts about this.

Harri

From list at fajar.net  Thu Aug 13 10:32:54 2020
From: list at fajar.net (Fajar A. Nugraha)
Date: Thu, 13 Aug 2020 17:32:54 +0700
Subject: [lxc-users] ghost services on LXC containers
In-Reply-To: <95e2f232-ce67-80b6-a34a-1529e16679f7@aixigo.com>
References: <c95b75b8-0e54-5d06-a78e-9da3834c12c6@aixigo.com>
 <95e2f232-ce67-80b6-a34a-1529e16679f7@aixigo.com>
Message-ID: <CAG1y0sesaM=onHgM2dF4gME9sewZ6nHPQbhhX3vbvoZNFFm-5w@mail.gmail.com>

On Thu, Aug 13, 2020 at 5:23 PM Harald Dunkel <harald.dunkel at aixigo.com> wrote:
>
> On 8/13/20 9:02 AM, Harald Dunkel wrote:
> >
> > # cat /sys/fs/cgroup/unified/system.slice/zabbix-agent.service/cgroup.procs
> > 0
> > 0
> > 0
> > 0
> > 0
> > 0
> >
> >
> > PID 0 is not valid here, AFAICT. And zabbix-agent isn't even installed
> > in my container. Its installed on the host only.
> >
>
> PS:
> Lennart Pottering wrote about this:
>
> Is it possible the container and the host run in the very same cgroup
> hierarchy?
>
> If that's the case (and it looks like it): this is not
> supported. Please file a bug against LXC, it's very clearly broken.
>
> (https://lists.freedesktop.org/archives/systemd-devel/2020-August/045022.html)
>
>
> I would be highly interested in your thoughts about this.


Try (two times, once inside the container, once inside the host):
- cat /proc/self/cgroup
- ls -la /proc/self/ns

-- 
Fajar

From harald.dunkel at aixigo.com  Thu Aug 13 10:47:41 2020
From: harald.dunkel at aixigo.com (Harald Dunkel)
Date: Thu, 13 Aug 2020 12:47:41 +0200
Subject: [lxc-users] ghost services on LXC containers
In-Reply-To: <CAG1y0sesaM=onHgM2dF4gME9sewZ6nHPQbhhX3vbvoZNFFm-5w@mail.gmail.com>
References: <c95b75b8-0e54-5d06-a78e-9da3834c12c6@aixigo.com>
 <95e2f232-ce67-80b6-a34a-1529e16679f7@aixigo.com>
 <CAG1y0sesaM=onHgM2dF4gME9sewZ6nHPQbhhX3vbvoZNFFm-5w@mail.gmail.com>
Message-ID: <40dc5afe-ec66-cadc-8559-c1c78319b59f@aixigo.com>

On 8/13/20 12:32 PM, Fajar A. Nugraha wrote:
> Try (two times, once inside the container, once inside the host):
> - cat /proc/self/cgroup
> - ls -la /proc/self/ns

On the host:

root at il08:~# cat /proc/self/cgroup
13:name=systemd:/
12:rdma:/
11:pids:/
10:perf_event:/
9:net_prio:/
8:net_cls:/
7:memory:/
6:freezer:/
5:devices:/
4:cpuset:/
3:cpuacct:/
2:cpu:/
1:blkio:/
0::/
root at il08:~# ls -la /proc/self/ns
total 0
dr-x--x--x 2 root root 0 Aug 13 12:40 .
dr-xr-xr-x 9 root root 0 Aug 13 12:40 ..
lrwxrwxrwx 1 root root 0 Aug 13 12:40 cgroup -> 'cgroup:[4026531835]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 ipc -> 'ipc:[4026531839]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 mnt -> 'mnt:[4026531840]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 net -> 'net:[4026531992]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 pid -> 'pid:[4026531836]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 pid_for_children -> 'pid:[4026531836]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 time -> 'time:[4026531834]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 time_for_children -> 'time:[4026531834]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 user -> 'user:[4026531837]'
lrwxrwxrwx 1 root root 0 Aug 13 12:40 uts -> 'uts:[4026531838]'


Entering the container:

root at il08:~# lxc-attach -n il02
root at il02:~# cat /proc/self/cgroup
13:name=systemd:/
12:rdma:/
11:pids:/
10:perf_event:/
9:net_prio:/
8:net_cls:/
7:memory:/
6:freezer:/
5:devices:/
4:cpuset:/
3:cpuacct:/
2:cpu:/
1:blkio:/
0::/
root at il02:~# ls -la /proc/self/ns
total 0
dr-x--x--x 2 root root 0 Aug 13 12:42 .
dr-xr-xr-x 9 root root 0 Aug 13 12:42 ..
lrwxrwxrwx 1 root root 0 Aug 13 12:42 cgroup -> 'cgroup:[4026532376]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 ipc -> 'ipc:[4026532313]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 mnt -> 'mnt:[4026532311]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 net -> 'net:[4026532316]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 pid -> 'pid:[4026532314]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 pid_for_children -> 'pid:[4026532314]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 time -> 'time:[4026531834]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 time_for_children -> 'time:[4026531834]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 user -> 'user:[4026531837]'
lrwxrwxrwx 1 root root 0 Aug 13 12:42 uts -> 'uts:[4026532312]'


I am not sure what this is trying to tell me, though. Is this the same
hierarchy? And would you agree that this is really a bad thing to do?

Harri