[lxc-users] limits.memory - possible to set per group of containers?

[Tomasz Chmielewski]

On 2019-06-18 11:59, Stéphane Graber wrote:

> So we have plans to introduce project quotas which will allow placing
> such restrictions in a clean way through LXD.
> 
> Until then you can manually tweak /sys/fs/cgroup/memory/lxc or
> /sys/fs/cgroup/memory/lxc.payload (depending on version of liblxc) as
> all containers reside under there and limits are hierarchical.
> 
> It's pretty similar to what systemd would attempt to do except that
> liblxc/lxd bypass systemd's expected cgroup so placing the limit 
> through
> systemd wouldn't work.

I was just going to test systemd - because systemd-cgls shows these:

1) this is just the monitor process, so setting any limits on it won't 
have the desired effect:

├─lxc.monitor
│ ├─shard01d
│ │ └─26025 [lxc monitor] /var/snap/lxd/common/lxd/containers shard01d
│ └─uni01-2019-06-18-01-09-11
│   └─11442 [lxc monitor] /var/snap/lxd/common/lxd/containers 
uni01-2019-06-18-01-09-11


2) Container processes seem to be all under lxc.payload tree:

─lxc.payload
│ ├─shard01d
│ │ ├─  488 /usr/sbin/mysqld --daemonize 
--pid-file=/var/run/mysqld/mysqld.pid
│ │ ├─ 1821 /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -d
│ │ ├─ 3158 /lib/systemd/systemd-udevd
│ │ ├─ 3878 /usr/sbin/rsyslogd -n
│ │ ├─ 4592 /sbin/rpcbind -f -w
(...)
│ └─uni01-2019-06-18-01-09-11
│   ├─ 2875 /usr/bin/php cli.php Jiradaemon
│   ├─ 3446 /usr/bin/php cli.php Jiradaemon
│   ├─ 4022 pickup -l -t unix -u -c
│   ├─ 4180 /usr/bin/php cli.php Jiradaemon

(...)


But since there isn't any "lxc.payload" systemd service - then yes, like 
you said - I'd need to dive into /sys/fs/cgroup/memory/ for now.

Great to hear project quotas are in the plans!


Tomasz Chmielewski