Tag Archives: server

GlusterFS

Example of GlusterFS configuration on 2 servers with Block Storage attached.

This setup is suggested for TESTING purposes only. In a production environment please verify performances.

Rackspace Cloud – .localdomain added in /etc/hosts after reboot

There is an agent called “nova-agent” which runs on all Rackspace cloud virtualised servers. This agent handles all communication between the hypervisor and guest OS, and is used for decloning.

Because it is used during decloning, it owns the /etc/hosts file and many files related to DNS and networking (/etc/resolv.conf , /etc/sysconfig/network-scripts/ifcfg-eth0 ,etc)

It is unlikely, but possible, that the host reboot triggered nova-agent to reset your hosts file.

To prevent nova-agent from overwriting your files, you can change the attributes of the file using the following command:

This will make the file unwriteable even to root! To remove this restriction, use the following:

Rackspace Cloud – Get AUTH Token

Linux Cloud Server migration script

This script allows you to migrate a Linux Server from one server to another one. It uses rsync and it could be use when you need to resize down a server for example, or if you want to migrate onto another Cloud Provider.

Source:
http://cloudnull.io/2012/07/cloud-server-migration/
https://github.com/cloudnull/InstanceSync

Rackspace – Cloud Monitoring – Ansible plugins

Install the required packages (Ubunto/Centos):

Prepare the virtual environment

Download the playbook

Install the required plugin:

To UNINSTALL the monitoring, you need to delete the check, removing the related file from /etc/rackspace-monitoring-agent.conf.d/ and restart the Cloud Monitoring agent.

Rackspace – Cloud server inaccessible after creation from custom image

It happens that sometimes a server built from a custom image is not accessible. Sometimes the reason is becase the Nova agent was not running (for various reasons) on the source server and the networking wasn’t set correctly during the building process. This means the new server still have the old IP and routes of the original, the one used to create the image itself.

How to fix it?
Connect on the console and make sure xe-linux-distribution (xe-daemon) and Nova Agent are restarted/up and running.

Important: Make sure xe-linux-distribution is started BEFORE Nova Agent is.

Once this has been done run the following command on the Cloud server to force the Hypervisor to re-push the right configuration (this works only on Linux servers):

Rackspace – Autoscale – Remove specific node (no replace)

Autoscale – remove specific node (without replacing)

Source

Rackspace – Cloud Sever autokill script