What’s Happening in OpenStack-Ansible (WHOA) – June 2016

The world of OpenStack moves quickly. Each day brings new features, new bug fixes, and new ways of thinking. The OpenStack-Ansible community strives to understand these changes and make them easier for operators to implement. The OpenStack-Ansible project is a collection of playbooks and roles written by operators for operators. These playbooks make it easier to deploy, maintain, and upgrade an OpenStack cloud. Keeping up with the changes in the OpenStack-Ansible project is challenging....

2016-06-15 · 7 min · Major Hayden

Xen 4.5 crashes during boot on Fedora 22

If you’re currently running a Xen hypervisor on a Fedora release before 22, stay put for now. There’s a bug in Xen when you compile it with GCC 5 that will cause your system to get an error during bootup. In my case, I’m sometimes getting the crash shortly after the hypervisor to dom0 kernel handoff and sometimes it’s happening later in the boot process closer to when I’d expect a login screen to appear....

2015-05-27 · 1 min · Major Hayden

Xen’s XSA-108 patch and Fedora

Xen’s latest vulnerability, XSA-108, has generated a lot of buzz over the last week. Most of the attention has come from the reboot notifications from large cloud providers (including my employer). The vulnerability allows a user within a guest to potentially read memory from another guest or the hypervisor itself. The window of available memory is small but it could be read many times over - much like how the Heartbleed vulnerability was exploited....

2014-10-02 · 2 min · Major Hayden

Performance benchmarks: KVM vs. Xen

After having some interesting discussions last week around KVM and Xen performance improvements over the past years, I decided to do a little research on my own. The last complete set of benchmarks I could find were from the Phoronix Haswell tests in 2013. There were some other benchmarks from 2011 but those were hotly debated due to the Xen patches headed into kernel 3.0. The 2011 tests had a good list of benchmarks and I’ve done my best to replicate that list here three years later....

2014-06-22 · 5 min · Major Hayden

Configure remote syslog for XenServer via the command line

Citrix has some helpful documentation online about configuring remote syslog support for XenServer using the XenCenter GUI. However, if you need to do this via configuration management or scripts, using a GUI isn’t an option. Getting it done via the command line is relatively easy: HOSTUUID=`xe host-list --minimal` SYSLOGHOST=syslog.example.com xe host-param-set uuid=${HOSTUUID} logging:syslog_destination=${SYSLOGHOST} xe host-syslog-reconfigure host-uuid=${HOSTUUID} Removing the configuration and going back to only local logging is easy as well:...

2014-06-03 · 1 min · Major Hayden

Xen hackathon coming up in London

If you enjoy using Xen, join members of the Xen Project community and Rackspace at the Xen Hackathon in London. The two day event starts on May 29th. Use these links to get more information: Hackathon announcement and travel/venue/registration information Discussion topics You don’t need to be a developer to join the event. It’s a great networking opportunity and you can take time to learn more about virtualization and how Xen works under the hood....

2014-03-27 · 1 min · Major Hayden

virt-manager: ‘NoneType’ object has no attribute ‘cpus’

After upgrading my Fedora 20 Xen hypervisor to virt-manager 1.0.0, I noticed that I couldn’t open the console or VM details for any of my guests. Running virt-manager --debug gave me the following traceback: Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/engine.py", line 803, in _show_vm_helper details = self._get_details_dialog(uri, uuid) File "/usr/share/virt-manager/virtManager/engine.py", line 760, in _get_details_dialog obj = vmmDetails(con.get_vm(uuid)) File "/usr/share/virt-manager/virtManager/details.py", line 530, in __init__ self.init_details() File "/usr/share/virt-manager/virtManager/details.py", line 990, in init_details for name in [c....

2014-03-06 · 1 min · Major Hayden

Installing Xen on Fedora 20

I’ve written about installing Xen on Fedora 19 and earlier versions on this blog before. Let’s tackle it on Fedora 20. Start with the Xen hypervisor and the basic toolset first: yum -y install xen xen-hypervisor xen-libs xen-runtime systemctl enable xend.service systemctl enable xendomains.service Get GRUB2 in order: # grep ^menuentry /boot/grub2/grub.cfg | cut -d "'" -f2 Fedora, with Linux 3.13.4-200.fc20.x86_64 Fedora, with Linux 0-rescue-c9dcecb251df472fbc8b4e620a749f6d Fedora, with Xen hypervisor # grub2-set-default 'Fedora, with Xen hypervisor' # grub2-editenv list saved_entry=Fedora, with Xen hypervisor # grub2-mkconfig -o /boot/grub2/grub....

2014-02-28 · 2 min · Major Hayden

A humble farewell to Seth Vidal

I was shocked to see Robyn Bergeron’s email today about Seth Vidal’s passing. He was the victim of a hit and run accident while he was cycling last night. The suspect has turned himself in as of tonight. I first met Seth at FUDCon Tempe back in 2011. We had talked off and on via email and IRC about cloud-related topics. He was interested in how we assembled our cloud offering at Rackspace and I was eager to talk to him about building cloud images and handling mirrors....

2013-07-10 · 2 min · Major Hayden

Installing the Xen hypervisor on Fedora 19

It’s been a little while since I last posted about installing Xen on Fedora, so I figured that Fedora 19’s beta release was as good a time as any to write a new post. To get started, you’ll need to get Fedora 19 installed on your favorite hardware (or virtual machine). Install the Xen hypervisor and tools. Also, ensure that both of the necessary daemons are running on each boot:...

2013-06-03 · 3 min · Major Hayden