tags: - postgresql - lxc categories: - informational comments: true

date: 2021-12-26 00:00:00

DESCRIPTION

Attempt to emulate production databases using linux containers. Can be used to test database take-over, replication settings, performance, etc…

ERRORS

VERIFICATION

COMMANDS

sudo apt install lxc lxc-templates lxc-utils cgroup-tools

sudo lxc-create -n db1 -t ubuntu -- -r focal -u test --password welcome
sudo lxc-create -n db2 -t ubuntu -- -r focal -u test --password welcome

set memory limit on container

cgroup settings will not work unless lxcfs is installed.

sudo apt install lxcfs

<https://github.com/lxc/lxc/issues/2845>

Hi, after install lxcfs, the free command in lxc container show the correct memory now, Thanks.

https://serverfault.com/questions/762598/will-linux-ubuntu-running-in-an-lxc-container-understand-cgroup-memory-limits

In PRD a database node - KVM - is allocated 1 CPU and 2 GB RAM.
Options: Create a KVM with 1 CPU and 2GB RAM or run container with memory and
CPU restriction.

Emulate containers with 1 CPU and 512MB RAM.

Testing

sudo lxc-cgroup -n db1 memory.soft_limit_in_bytes 536870912 sudo lxc-cgroup -n db1 memory.limit_in_bytes 536870912

sudo lxc-cgroup -n db1 cpuset.cpus 0

Permanent

sudo vi /var/lib/lxc/db1/config

… lxc.cgroup.memory.limit_in_bytes = 536870912 lxc.cgroup.memory.max_usage_in_bytes = 536870912

lxc.cgroup.cpuset.cpus = 0

Start the containers

sudo lxc-start -n db1 # 10.0.3.11 sudo lxc-start -n db2 # 10.0.3.111 “`