Skip to main content
  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


ijlal-loutfi
6 March 2026

Sovereign clouds: enhanced data security with confidential computing 

Confidential computing Article

Increasingly, enterprises are interested in improving their level of control over their data, achieving digital sovereignty, and even building their own sovereign cloud. However, this means moving beyond thinking about just where your data is stored to thinking about the entire data lifecycle.  In this blog, we cover the differences betwe ...


Massimiliano Gori
2 March 2026

Supporting more identity providers on Ubuntu with the new Authd OIDC broker

Cloud and server Article

Today we are announcing the general availability of the new generic OpenID Connect (OIDC) broker for Authd. With enterprises needing to centralise access management controls, the ability to choose your own identity solution is paramount. This new broker snap is our answer to that need, allowing Ubuntu Desktop and Server to integrate with ...


Bertrand Boisseau
2 March 2026

Cloud-native Android™ infotainment: your CI pipeline shouldn’t depend on hardware

Automotive Article

More and more often, infotainment systems are being developed and delivered like software, yet often they are still tested and validated using hardware-centric processes. This is far from ideal: access to devices is limited, environments are difficult to reproduce, and iteration slows down as soon as multiple teams need to work in paralle ...