Category: Linux

Linux stuff

RDO live migration/block migration

Pre-requisisities: Install CentOS Virt SIG repository centos-release-qemu-ev for qemu-kvm which supports live migration https://bugs.centos.org/view.php?id=8281 yum install centos-release-qemu-ev yum update / yum install qemu-kvm Getting below error when doing ‘nova live-migration –block-migrate <instance-name> <dest host>‘ 2016-08-30 17:38:35.743 8360 ERROR nova.virt.libvirt.driver [req-9d7fb54d-2ca8-4916-bad0-2c0bc0426466…

Linux performance tidbits

Netflix originated: Linux Performance Analysis in 60,000 Milliseconds Netflix at Velocity 2015: Linux Performance Tools Brendan Gregg’s Linux Performance Ubuntu: Disk performance Redhat: Red Hat Enterprise Linux 6 Performance Tuning Guide Red Hat Enterprise Linux 7 Performance Tuning Guide

Software inventory with facter

Getting hash of installed software with facter: #!/usr/bin/ruby # # File: /your/puppetdir/modules/yourmodule/lib/facter/sw_inventory.rb # # Description: Report versions of installed software # require ‘facter’ Facter.add(:sw_inv) do setcode do # OSX if Facter.value(:osfamily) == ‘Darwin’ require ‘facter/util/macosx’ sw_inv = {} # Lists…

YASPI

Case: yum fails: http://yum.puppetlabs.com/el/6/dependencies/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 – “Failed to connect to 2600:3c00::f03c:91ff:fe69:6bf0: Network is unreachable” in a machine which doesn’t have IPv6 connectivity Solution: Since connections go through proxy, define it to respective repo config Root cause:…

HTML info page from pdfs in a directory

Script uses pdfinfo to get information from pdf-files in directory and prints that in a webpage, put it in a webserver directory along pdfs Prereqs: pdfinfo #!/bin/sh # # Digs info from pdf and presents it in htmlpage # INFOCMD=”/usr/bin/pdfinfo”…

Federated VoIP

Noted that Fedora 19 Alpha has a feature called federated VoIP, debian has also described their unified communications opentelecoms.org has description about federated VoIP here – clips – The vision is true peer-to-peer VoIP, with no central point of control.…