Skip to main content

Your submission was sent successfully! Close

Thank you for signing up for our newsletter!
In these regular emails you will find the latest updates from Canonical and upcoming events where you can meet our team.Close

Thank you for contacting us. A member of our team will be in touch shortly. Close

  1. Blog
  2. Article

Canonical
on 17 June 2014

OpenStack One-Liners

One-line bash commands for managing, deploying and testing OpenStack and related components, hypervisors and containers.  Some simple and obvious, some cool and questionable, hopefully all useful.  Check back on this post, I’ll likely add more. #1 – Watch Nova Compute for Non-Active Instances on Openstack Outputs total instance count and non-active instances. Useful for keeping an eye on potential problem VMs in a PAUSED, ERROR, SHUTOFF or other non-active state. Command: watch --interval=1 'nova list --all-tenants | wc -l && nova list --all-tenants | grep -v "ACTIVE"' #2 – Ping a List of Hosts Forever:  1-Line Loop A simple one-line while loop containing a for loop to ping a list of hosts each with one packet, followed by a 1/4 second iteration delay and an output text filter. Command: while true; do for h in bcu vxu rbu; do ping ${h} -c 1 | grep ttl; sleep 0.25; done; done;   #3 – Watch Cinder Volumes and Snapshots and Glance Images in Openstack Useful for working with volumes, snapshots and images in small Openstack deployments. watch --interval=1 "cinder list && cinder snapshot-list && glance image-list"   #4 – Watch Linux Containers and Directory-Backed Storage I find this one handy when I need to monitor LXC containers on Ubuntu Server – Precise Pangolin, Trusty Tahr, Utopic Unicorn and later.  The Ubuntu Server Guide has a detailed section on LXC usage. watch "sudo lxc-ls --fancy --nesting && sudo ls -Ralh /var/lib/lxc/"   #5 – Watch Your Disk Space Disappear This is a tail-style output of the free space on /. while true; do df -h / | grep '/' | awk '{ print $4 }'; sleep 1; done 6.1G 6.1G 6.0G 6.0G 5.9G 5.8G 5.7G 5.7G  

Related posts

Canonical
25 June 2025

Native integration now available for Pure Storage and Canonical LXD

Canonical announcements Article

Canonical, the company behind Ubuntu, and Pure Storage, the IT pioneer delivering enterprise-grade all-flash storage, have partnered to introduce a native integration between LXD and Pure Storage FlashArray. This collaboration allows organizations to combine open source virtualization with industry-leading block storage to achieve unmatch ...

Lyubomir Popov
23 June 2025

Revolutionizing Web Page Creation: How Structured Content is Slashing Design and Development Time

Ubuntu Article

Co-authored with Julie Muzina A year ago, during our Madrid Engineering Sprint, we challenged ourselves to dramatically reduce, or even eliminate, the need for constant design involvement in the day-to-day creation of web pages. Our strategy for achieving this is based on a smarter, more structured approach to content. The Challenge: Brid ...

Canonical
23 June 2025

Ubuntu Core is now available on MediaTek’s Genio platform

IoT Article

This is the first optimized Ubuntu Core image available on MediaTek’s Genio 350, 510, 700, and 1200 platforms released under the strategic partnership between Canonical and MediaTek Inc.  Today Canonical, the publisher of Ubuntu, and MediaTek announce the official Ubuntu Core launch of the very first optimized Ubuntu Core image for MediaT ...