• How to automatically extend windows virtual disk size [Openstack]

    Thanks to this article – how to create a Windows Image for OpenStack Glance repository.  After uploading the image, I created a separate flavor for Windows VMs with 2 vCPUs, 4GB RAM, and 40GB disk. However, when the Windows VM is booted, I noticed the hard disk space of 20GB,…

  • No such file or directory c++ Error [CentOS]

    While installing pip packages through the requirements file on the minimal CentOS Stream 8 server with python v3.7, encountered the error “No such file or directory c++” during the installation of grpcio package. Below is the complete error message: # pip3 install -r requirements.txt WARNING: Running pip install with root…

  • How to configure Open vSwitch bridge for OpenStack

    Followed the guide from server-world for installing the OpenStack Train version on the CentOS server. Configuring neutron services requires physical access to the terminal, as it requires a restart of the network services. But sometimes, you don’t get to be present in front of the physical terminal and end up…

  • Too many connections for neutron-db-manage [MySQL]

    While finalizing the installation of neutron on controller node, the operation to populate the database failed with Too many connections for neutron-db-manage. Below is the complete error: # su -s /bin/bash neutron -c “neutron-db-manage –config-file /etc/neutron/neutron.conf –config-file /etc/neutron/plugins/ml2/ml2_conf.ini upgrade head” Traceback (most recent call last): File “/usr/bin/neutron-db-manage”, line 10, in…

  • How to manually install higher version of PIP for Python v2.7

    On my CentOS 7 minimal server installation, I installed python-pip using YUM. However, the version it has installed is 8.1.2 for Python version 2.7 though the latest version is 22.3.1. Some of the packages needs a higher version of pip atleast above 9.0.1. When tried to upgrade using pip install…

  • [CentOS 7]: Yum install python-pip | No package python-pip available

    I am trying to install python-pip on CentOS 7 minimal server. However, I got the error No package python-pip available. Below is the complete error message. # yum install python-pip Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.vhost.vn * centos-ceph-nautilus: mirrors.vhost.vn * centos-nfs-ganesha28: mirrors.vhost.vn * centos-qemu-ev:…

  • [CentOS Stream 8]: Error: Unknown repo epel [Solved]

    I was given a task to install OpenStack Yoga release on CentOS Stream 8 Server (minimal Server). I followed the Server World guide for the installation. While installing Keystone using the below command, encountered the error “Unknown repo epel“. # dnf –enablerepo=centos-openstack-yoga,epel,powertools -y install openstack-keystone python3-openstackclient httpd mod_ssl python3-mod_wsgi python3-oauth2client…

  • [OpenStack Glance]: Failed to contact the endpoint at https://localhost:9292 for discovery.

    After the successful installation of OpenStack Glance, connecting to the Glance API (on port 9292) fails with an error message “failed to contact the endpoint at https://controller.tg.com:9292 for discovery. Fallback to using that endpoint as the base url“. Below is the complete error message: Failed to contact the endpoint at…

  • [CentOS Stream 8]: Unknown repo crb : [Solved]

    While executing the below command, encountered the error “Unknown repo crb“. # dnf –enablerepo=centos-openstack-yoga,epel,crb -y install openstack-glance Error: Unknown repo: ‘crb’ Solution: CRB is known as  CodeReady Linux Builder. However, it is trademarked, and as such, available only in CentOS which has a different name – PowerTools. The PowerTools repository…

  • [OpenStack]: Yum RabbitMQ installation error on CentOS Stream 8

    While installing the OpenStack Yoga release, after the yum repository setup from the server-world guide, RabbitMQ server installation error showed up as below: [root@controller ~]# dnf -y install rabbitmq-server memcached nginx-mod-stream Last metadata expiration check: 0:00:34 ago on Mon 14 Nov 2022 10:25:26 AM IST. Error: Problem: package erlang-lager-3.8.0-2.el8.noarch requires…

  • [Firefox]: Error code: SSL ERROR HANDSHAKE UNEXPECTED ALERT

    In recent times, on Firefox v102.3.0esr (64-bit) encountered trouble in viewing GMAIL and few other SSL enabled websites with the error message  SSL ERROR HANDSHAKE UNEXPECTED ALERT. However, the same is working fine on Chrome browser. I tried disabling, Anti-Virus, cleared browser cache, etc., but all in VAIN! Secure Connection…

  • How to stop Windows10 VM on OpenStack from automatically restarting!

    I’m experiencing a Windows10 VM on OpenStack that automatically restarts on successful autologon. Struggling with this for a while and hours spent in search of this topic on google went in vain. Followed the below step-by-step procedure to find the root cause and stop Windows10 VM on OpenStack from automatically…

  • Increase virtual disk size of Windows10 VM on QEMU-KVM

    Recently I created a windows image using QEMU-KVM and ported it onto OpenStack for one of my clients. While creating the windows image I had set the virtual disk size as 40GB. However, the client requested an additional virtual disk of 10GB. In this article, we shall learn how to…

  • Why Windows10 VM is slow on OpenStack?

    Before we proceed, please read Why does Windows 10 VM show 100% CPU utilization always on QEMU-KVM? The same issue holds for Windows10 VM on OpenStack making it slow and using 100% CPU utilization always. This article shows how to configure OpenStack to run Windows10 VM on a multicore processor utilizing…

  • Why does Windows 10 VM shows 100% CPU utilization always on QEMU-KVM?

    You might have read my article on How to Create Windows image for OpenStack and its related articles such as fixing Windows could not parse or process the unattended answer file for Pass Specialize, and How to configure Windows VM Autologin for OpenStack Cloud. To add to the series, here…

  • Configure Apache for WebSockets using Reverse Proxy

    I used WebSockify in my web application to connect to the VNC server using noVNC to enable remote access to Linux servers via the browser. It was an easy implementation as there was no firewall involved and the WebSocket port was opened. However, recently I had to migrate to another…

  • SELinux: Cannot write into “Config” directory! [OwnCloud]

    I installed owncloud with all the necessary pre-requisites and when tried to access over the browser encountered error: Cannot write into “Config” directory! Below is the complete error list. How to fix Cannot write into “Config” directory! [OwnCloud] The error above clearly conveys that, the webserver is unable to write…

  • How to start GUI on Ubuntu Linux Machine

    Earlier I had written an article on How to start GUI on CentOS 8. After this article was read by one of my readers, he asked me to write a similar article for Ubuntu. Typically any Linux servers (CentOS or Ubuntu) don’t provide Graphical User Interface (GUI) as it adds…