Category Archives: Virtualization

In computing, virtualization refers to the act of creating a virtual version of something, including virtual computer hardware platforms, storage devices, and computer network resources.

What is: chroot – the system call and utility in Linux

23 March 2019

 chroot() was added to the Version 7 Unix in 1979 and used for filesystem isolation. In fact, it’s the predecessor of the whole current containerization idea, just now there are namespaces and cgroups are used while earlier chroot was used to create an environment which is isolated from a host and can be used for… Read More »

AWS: CLI named profiles

19 March 2019

 AWS CLI supports so-called named profiles stored in the configuration file .aws/config and ~/.aws/credentials file with keys which by default contains the… Well – the “default” profile. An additional profile can be added using the aws configure command with the –profile option. Here is an example of such file with already existing two profiles:

Terraform: creating a project with an AWS EC2, VPC, and AWS cross-region VPC peering connection

18 March 2019

 One of the disappointing surprises in my AWS CloudFormation experience was the fact that it wasn’t able to automatically create cross-region VPC-peering connections. Note: this post originally was written in Rus on 28 June 2018 but now CloudFormation can do it, check the PeerRegion parameter of the AWS::EC2::VPCPeeringConnection resource. As a result – it tries… Read More »

Terraform: main commands, state-files, backend storages, and modules in examples on AWS

17 March 2019

 Examples of how to use Terraform, work with its backends and modules. Here will set up a simple EC2 instance in AWS and will store Terraform’s state-files in an AWS S3 bucket. In short terms – but with real examples and links to documentation. Installation on Arch Linux: For authorization will use an existing AWS… Read More »

NextCloud: installing server on Debian behind NGINX with PHP-FPM and client on Arch Linux

17 March 2019

 After the news that Dropbox adds a new limitation for users by the three devices only – I’m finally ready to install my own NextCloud to store and synchronize data. The sad thing is not exactly the three devices limit (and it will be applied for a new users only – old user who already… Read More »

VirtualBox: Nonexistent host networking interface, name ‘wlp13s0’

11 March 2019

 Have the ~/VirtualBox VMs directory copied from my old laptop to a new PC. Now during VM’s launch – VirtualBox says: Nonexistent host networking interface, name ‘wlp13s0’ (VERR_INTERNAL_ERROR). Result Code: NS_ERROR_FAILURE (0x80004005) Component: ConsoleWrap Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed} Check interfaces on the new PC: Exit (!) from VirtualBox. Edit VM’s file directly. It will be the… Read More »

Prometheus: RTFM blog monitoring set up with Ansible – Grafana, Loki, and promtail

10 March 2019

 After implementing the Loki system on my job’s project – I decided to add it for myself, so see my RTFM blog server’s logs. Also – want to add the node_exporter and alertmanager, to be notified about high disk usage. In this post, I’ll describe the Prometheus, node_exporter, Grafana, Loki, and promtail set up process… Read More »

AWS: RDS logs, export to the CloudWatch Logs and CloudFormation template

7 March 2019

 We have a bunch of the AWS RDS with MariaDB. Backend-developers asked me to enable slow requests logs so they can debug their application. So the task is: enable AWS RDS logging and configure export to the CloudWatch Logs for further analysis. As everything else – our RDS instances are configured via CloudFormation templates, so… Read More »

Linux: The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv

5 March 2019

 After each new VirtualBox installation – I’m stepping on the same rake again and again and have to go to Google to ask: The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv Attempt to load vboxdrv manually also provides the error: And looks like kernel version… Read More »

OpenVPN: OpenVPN Access Server set up and AWS VPC peering configuration

21 February 2019

 OpenVPN Access Server is ready to use OpenVPN server which requires minimal configuration. The free version allows you to have two clients. If you need more – you can buy additional licenses. Infrastructure description Currently to access our resources such as Jenkins, Nexus etc we are using Allow Rules in AWS Security Groups where each user… Read More »