romansavrulin

Proxmox with LVM-thin and why we should use Trim/Discard

Excerpts from the Proxmox VE Administration Guide]

LVM normally allocates blocks when you create a volume. LVM thin pools instead allocates blocks when they are written. This behaviour is called thin-provisioning, because volumes can be much larger than physically available space.

8.10.2. Trim/Discard It is good practice to run fstrim (discard) regularly on VMs and containers. This releases data blocks that the filesystem isn’t using anymore. It reduces data usage and resource load. Most modern operating systems issue such discard commands to their disks regularly. You only need to ensure that the Virtual Machines enable the disk discard option.

romansavrulin

Reddit post (Archived)

Table of Content

• What to expect?
  • Some TLDR about the idea behind
• Prerequisites
  • Hardware
  • System & Software
• Update: Attention for MUXless laptop

romansavrulin

How to mount a qcow2 disk image

This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.

Step 1 - Enable NBD on the Host

modprobe nbd max_part=8

romansavrulin

HP Smart Storage Admin CLI (ssacli) installation and usage on Proxmox PVE (6.x)

Why use HP Smart Storage Admin CLI?

You can use ssacli (smart storage administrator command line interface) tool to manage any of supported HP Smart Array Controllers in your Proxmox host without need to reboot your server to access Smart Storage Administrator in BIOS. That means no host downtime when managing your storage.

CLI is not as convenient as GUI interface provided by BIOS or desktop utilities, but still allows you to fully manage your controller, physical disks and logical drives on the fly with no Proxmox host downtime.

ssacli replaces older hpssacli, but shares the same syntax and adds support for newer servers and controllers.

Installation

romansavrulin

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

romansavrulin

new Date().format("yyyy-MM-dd'T'HH:mm:ss'Z'", TimeZone.getTimeZone("UTC")) 

romansavrulin

rm -rf ~/Library/Application\ Support/Slack/
rm -rf ~/Library/Containers/com.tinyspeck.slackmacgap/
rm -rf ~/Library/Preferences/com.tinyspeck.slackmacgap.plist
rm -rf ~/Library/Saved\ Application\ State/com.tinyspeck.slackmacgap.savedState 
rm ~/Library/Safari/LocalStorage/*slack*

romansavrulin

#!/usr/bin/env python3
"""
Very simple HTTP server in python for logging requests
Usage::
    ./server.py [<port>]
"""
from http.server import BaseHTTPRequestHandler, HTTPServer
import logging

class S(BaseHTTPRequestHandler):

romansavrulin

This gist aims to explain the difference between stubs and mocks and when each should be used. For an introduction to stubs and mocks, start somewhere else, like here.

 

• Stub: used to isolate the object under test from its dependencies, preventing the test from being influenced by code outside the object. This way the test can't be made to fail or be broken by code which is not part of the specific functionality being tested. Stubs also lead to less code being run, which helps keep tests fast. A stub has no expectations. It doesn't care if it is called or how many times.

  For example, you might stub out a message sent to a database connection if all you are trying to test is the type of the method's return value.

 

romansavrulin

  gem 'lograge' # more readable logs
    gem 'logstash-event' # for logstash json format
  gem 'mono_logger' # threadsafe logging