Lxc- Introduction

LXCIntroduction

Luıs [email protected]

Federal University of Pernambuco

November 2014

Luıs Eduardo [email protected] (UFPE) LXC November 2014 1 / 19

Summary

1 Definition

2 General

3 ImplementationsMain implementations

4 Using LXCInstallationBasic UsageAdvanced Use


Definition

Linux Containers (LXC for LinuX Containers) are lightweight virtualmachines (VMs) which are realized using features provided by amodern Linux kernel – VMs without the hypervisor.

Operational system-level virtualization method for running multiplesand isolated systems (containers) on a single host.


General

Lightweight process virtualization is not new

Chroot

Solaris Zones

BSD jails

AIX WPARs (Workload Partitions)

Linux-based containers projects

Why now?

Kernel Support +3.8(Febuary 2013)

NamespacesCgroups


Implementations

Figure: Several ways to use container. Source:Wikipedia


Summary

1 Definition

2 General




Main implementations

LXC

Mostly written in C

Stable and mature codebase

Docker

Mostly written in Go


Similar architecture with configuration management

OpenVZ

Mostly written in C


Project that gave rise to several other


Summary

1 Definition

2 General




Installation

Debian distributions

$ sudo apt-get install lxc


Summary

1 Definition

2 General




Usage

Test installation:

Check configurations

$ sudo lxc-checkconfig

Figure: lxc-checkconfig output


Usage

Your first container:

Run first container

$ sudo lxc-create -t ubuntu -n ubuntulxc

Where:

-t : template

-n : name of container


Usage

See information about new container:

Container information

$ sudo lxc-ls -f

Start new container:

Start new container

$ sudo lxc-start -n ubuntulxc


Usage

Stop a container

$ sudo lxc-stop -n ubuntulxc

Destroy a container

$ sudo lxc-destroy -n ubuntulxc

Clone a container

$ sudo lxc-clone -o ubuntulxc -n ubuntulxc2

Execute a temporary container

$ sudo lxc-execute -n guest – sleep 100


Summary

1 Definition

2 General




Advanced Use

Containers storage: /var/lib/lxc/

Main configuration file: /var/lib/lxc/YOUR CONTAINER/config

Cgroups files: /sys/fs/cgroup/.../lxc/YOUR CONTAINER/

Scripts to install some templates: /usr/share/lxc/templates


Advanced Use

Controlling Container Resources

CPU information

$ sudo lxc-cgroup -n ubuntulxc cpuset.cpus

CPU time and block I/O access

$ sudo lxc-cgroup -n ubuntulxc cpu.shares 256$ sudo lxc-cgroup -n ubuntulxc blkio.weight 500

Dynamic Memory Allocation

$ sudo lxc-cgroup -n ubuntulxc memory.soft limit in bytes 268435456$ sudo lxc-cgroup -n ubuntulxc memory.limit in bytes 53687091

More cgroups here.


https://docs.oracle.com/cd/E37670_01/E37355/html/ol_cgroups.html

References

LXC Ubuntu. Available at:https://help.ubuntu.com/lts/serverguide/lxc.html.

Oracle Documentation. Available at:https://docs.oracle.com/cd/E37670 01/E37355/html/ol cgroups.html.

Arch Linux Containers. Available at:https://wiki.archlinux.org/index.php/Linux Containers.

Wikipedia LXC. Available at: http://en.wikipedia.org/wiki/LXC.

Rathore, Muhammad Siraj, Markus Hidell, and Peter Sjodin. ”KVMvs. LXC: comparing performance and isolation of hardware-assistedvirtual routers.” American Journal of Networks and Communications2.4 (2013): 88-96.


LXCIntroduction

Luıs [email protected]

Federal University of Pernambuco

November 2014


Lxc- Introduction

Technology

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