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


Miguel Divo
21 November 2025

Open design: the opportunity design students didn’t know they were missing

Design Design

What if you could work on real-world projects, shape cutting-edge technology, collaborate with developers across the world, make a meaningful impact with your design skills, and grow your portfolio… all without applying for an internship or waiting for graduation? That’s what we aim to do with open design: an opportunity for universities ...


Bertrand Boisseau
21 November 2025

Anbox Cloud 1.28.0 is now available!

Ubuntu Article

Enhanced Android device simulation, smarter diagnostics, and OIDC-enforced authentication The Anbox Cloud team has been working around the clock to release Anbox Cloud 1.28.0! We’re very proud of this release that adds robust authentication, improved diagnostic tools, and expanded simulation options, making Anbox Cloud even more secure, f ...


Canonical
18 November 2025

83% of organizations see value in adopting open source, but report major gaps in security and governance

Canonical announcements Article

A new Linux Foundation report reveals how organizations worldwide are adopting, using, and perceiving open source software. The Linux Foundation’s latest report, The state of global open source, has just been released in collaboration with Canonical. The report follows the Linux Foundation’s European spotlight report, released earlier thi ...