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

An error occurred while submitting your form. Please try again or file a bug report. 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

Bertrand Boisseau
5 December 2025

From cloud to dashboard: experience the future of infotainment development at CES 2026

Automotive Article

This year, we’re excited to show a demo that combines the strengths of both Anbox Cloud and Rightware’s Kanzi, the industry-leading software for creating rich, visually stunning infotainment interfaces. ...

Canonical
2 December 2025

Canonical announces Ubuntu Pro for WSL 

Canonical announcements Article

Ubuntu Pro for WSL provides turnkey security maintenance and enterprise support for Ubuntu 24.04 LTS WSL instances in Windows. The subscription will also enable comprehensive management for system administrators.  Today, Canonical announced the general availability of Ubuntu Pro for WSL which can be installed from the Microsoft Store. Sou ...

Canonical
1 December 2025

Canonical announces general availability of Ubuntu on Qualcomm Dragonwing™ IQ-9075 platform

Ubuntu Article

December 1, 2025 – Canonical, the publisher of Ubuntu, today announced the availability of certified images for the Qualcomm Dragonwing™ IQ-9075 platform. This high-performance industrial platform is now fully supported with optimized images for Ubuntu 24.04 LTS. The certified images are available for both Ubuntu Server and Desktop, equip ...