Linux Compute Node Installation

Modified: 28 Apr 2022 01:26 UTC

Prerequisites

Platform Image / Process / Installation

Linux CN platform images are available in Manta at https://us-east.manta.joyent.com/Joyent_Dev/public/TritonDCLinux

It is advised to reboot all Linux Compute Nodes to the latest available platform. Before filing any bugs, issues must be tested on the latest platform with all agents up to date.

Use the following commands to install the latest platform image:

mkdir /var/tmp/linuxcn
cd /var/tmp/linuxcn
curl -o https://us-east.manta.joyent.com/Joyent_Dev/public/TritonDCLinux/joyent-debian_live-latest.usb.gz
sdcadm platform install ./joyent-debian_live-latest.usb.gz

You can then use sdcadm platform assign as normal. Note that platforms can only be assigned to the same OS type or an unsetup CN.

Networking

Please take special note that all NICs assigned to LXC instances behave as if allow_ip_spoofing, allow_mac_spoofing, allow_dhcp_spoofing, and allow_unfiltered_promisc are enabled, due to how Linux handles networking for containers. Please note, LXC instances should not be run by untrusted end users in shared networks due to their ability to spoof IP addresses on shared subnets or networks. Dedicated vlans for LXC instances, or trusted network pools should only be available for LXC instances. In order to disallow LXC instances from being deployed to shared networks, use of LXC separate packages, images or users should be granted access with specific network ownership to test these instances.

Linux CNs use nic_tags as normal. CNs must be rebooted before nic_tag changes will take effect.

Importing Supported Images

LXD images provided by linuxcontainers.org or Canonical used with Triton must meet the following requirements.

Images must:

To import images, first use the lxd command on a running Linux CN to list images from either the images: or ubuntu: remote.

lxc image list images:
lxc image list ubuntu:

Once you have the list of images, choose a suitable image, such as debian/11/cloud or ubuntu:f. On the Triton headnode, call the API to import the image. Note that images can currently only be imported by the alias.

sdc-imgapi /images?action=import-lxd-image\&alias="debian/11/cloud" -X POST

Images are initially only usable by the admin user. You will need to add individual users to the image ACL or make the image public. Refer to the imgapi documentation for details. You may also use the AdminUI web interface to set the ACL.

Packages

Special package traits are not needed, but traits may be applied to CNs and packages as normal. Operators that prefer to utilize separate LXC packages for LXC instances may use traits or brands to isolate LXC Instances to specific packages.

Known Triton Gaps / Divergences / Issues

Linux LXC containers do not support the following Triton features.

CPU Capacity Management

CPU capacity management uses different mechanisms on Linux. This means that when a compute node is not under load, instances are able to burst higher and for longer without CPU scheduling by Triton, utilizing native Linux cpu scheduling features. This may give the false impression that performance is “degraded” when the CN is under high load. This is not in fact the case. When a CN is under high load, all instances are guaranteed a minimum performance relative to the chosen package and the number/speed of the physical processors. The fact that an instance can consume more than its fair share when load is low does not mean that instances are being deprived of CPU time when load is high.

To put this into Triton/SmartOS terms, LXC instances running on a LinuxCN are allowed unlimited bursting as long as there is bursting capacity available.

Getting Help

Questions, bugs or other comments can find us watching on IRC, mailing list or contacting your account manager if you have enterprise support. We will update this page as gaps are closed and improvements are merged & released.