"zpool iostats" for humans; find the slow parts of your ZFS pool

Overview

Getting the gist of zfs statistics

vpool-demo.mp4

The ZFS command "zpool iostat" provides a histogram listing of how often it takes to do things in parts of your pool. It's useful to find bottlenecks and problem devices, but it's also kind of hard to read, with the nearly 4000 mixed-unit numbers.

What's a histogram?

A histogram is an arrangement of data to show how measurements can be different and how often. For instance, last year, 60 times it took Joe 3-to-4 hours to drive to Albequerque, and 20 times it took 4-to-5 hours, 80 times it took 5-to-6 hours, and 2 times it took 6-to-7 hours. That 60-times & 20-times & 80-times & 2-times is a histogram showing population of the buckets of driving-times. It can help you understand the pattern of likelihoods. It seems when Joe has a traffic problem, it's usually pretty big; and problems happen more often than not; but sometimes it's a breeze.

count 0 60 20 80 2 0 times
bucket 0 to 3 3 to 4 4 to 5 5 to 6 6 to 7 7 to 8 hours

Mentally sizing the huge absolute numbers from ZFS

The exact number of items in a histogram bucket does not matter at all. 36778213 ZFS operations vs 39214291 isn't a good comparison for humans to try to make. For understanding what's happening in your ZFS pool, the gist and relative sizes is what's important, so the numerical output of the "zpool iostat" tool is harder to understand than it needs to be. That's the problem this tool aims to fix.

The tools here will summarize and display relative sizes of those numbers, side-by-side, to help you see what's important.

Simplified output compares all devices for a given statistic

Simplified output shows all stats of a device at once

You can help!

There are some opinionated coloring of time herein, and those opinions are not well-informed. If you have a suggestion on how to better slice up the six white-to-red colors of time, please file a ticket. Mention the your (at max) five thresholds to the next color plateau, in nanoseconds.

Also, if the tool crashes, please file a ticket with the output. Include the stack trace.

Meanings of output

The histogram uses both colors to show relative population, but also glyphs. The glyphs are "." meaning the smallest but nonzero, "a" up through "z", and "^" represents the highest number among the buckets. The glyphs represent linear-growing, equidistant-apart number ranges. "f" is 4 times farther away from "b" than "c" is from "b".

Usage and prerequisites

To run, have Python 3.4 or greater, and run it with the pool name(s) as parameter.

$ zpool-iostat-viz

$ zpool-iostat-viz tank1 tank2

$ zpool-iostat-viz tank vdev42 vdev90 vdev163

$ zpool-iostat-viz -d

It displays data points in the histogram as letters of the alphabet, scaled and colored to show hot-ness of that bucket. It's scaled so that each column has a most-filled "^", and the rest of the letters show relative population vs the most populous bucket.

Also useful is the differential updates mode, which you can select with "-d" parameter. It's like stats are reset every three seconds, so you can see what's happening right now with your pool, not since boot.

Press arrows to move stats, and press q to quit. "--help" argument to see what other options you have.

Owner
Chad
Probably going out like Aeschylus.
Chad
Unofficial GoPro API Library for Python - connect to GoPro via WiFi.

GoPro API for Python Unofficial GoPro API Library for Python - connect to GoPro cameras via WiFi. Compatibility: HERO3 HERO3+ HERO4 (including HERO Se

Konrad Iturbe 1.3k Jan 01, 2023
Python based Algo trading bot for Nifty / Banknifty futures and options

Fully automated Alice Blue Algo Trading with Python on NSE and MCX for Nifty / Crude / Banknifty futures and options , absolutely FREE ! This algo tra

Rajesh Sivadasan 49 Dec 31, 2022
Semplice pagina di informazione per sapere se e quando è uscito Joypad, il podcast a tema videoludico di Matteo Bordone (Corri!), Francesco Fossetti (Salta!) e Alessandro Zampini (Spara! per finta).

È uscito Joypad? Semplice pagina di informazione per sapere se e quando è uscito Joypad, il podcast a tema videoludico di Matteo Bordone (Corri!), Fra

Paolo Donadeo 32 Jan 02, 2023
Telegram Bot for saving and sharing personal and group notes

EZ Notes Bot (ezNotesBot) Telegram Bot for saving and sharing personal and group notes. Usage Personal notes: reply to any message in PM to save it as

Dash Eclipse 8 Nov 07, 2022
ByDiego Token Grabber is a Discord Stealer

ByDiego Token Grabber is a Discord Stealer. This way you can get too much information from x person if you pass it on and open it

zByDiegoM.T 4 Mar 11, 2022
Python library for the eWarehousing Solutions API.

eWarehousing Solutions Python Library This library provides convenient access to the eWarehousing Solutions API from applications written in the Pytho

eWarehousing Solutions 2 Nov 09, 2022
Telegram Group Chat Statistics With Python

Telegram Group Chat Statistics How to Run First add PYTHONPATH in repository root directory enviroment variable by running: export PYTHONPATH=${PWD}

Sina Nazem 3 Apr 18, 2022
Python Client Library to interface with the Phoenix Realtime Server

supabase-realtime-client Python Client Library to interface with the Phoenix Realtime Server This is a fork of the supabase community realtime client

Anand 2 May 24, 2022
Connect your Nintendo Switch playing status to Discord!

Disclaimer: Unfortunately, it appears that Nintendo has removed returning self-Presence in their API as of recently, making this project near obsolete

Deltaion Lee 145 Dec 30, 2022
A discord bot written in discord.py to manage custom roles assigned to boosters of your server.

BBotty A discord bot written in discord.py to manage custom roles assigned to boosters of your server. v0.0.1-alpha released! This version is incomple

Oui002 1 Nov 27, 2021
Google scholar share - Simple python script to pull Google Scholar data from an author's profile

google_scholar_share Simple python script to pull Google Scholar data from an au

Paul Goldsmith-Pinkham 9 Sep 15, 2022
"zpool iostats" for humans; find the slow parts of your ZFS pool

Getting the gist of zfs statistics vpool-demo.mp4 The ZFS command "zpool iostat" provides a histogram listing of how often it takes to do things in pa

Chad 57 Oct 24, 2022
✨ A simple project to automate some stuffs in Habbo with G-Earth ✨

⚡️ Habbo G-Earth extensions ⚡️ ✨ A simple project to automate some stuffs in Habbo with G-Earth ✨ About | Getting Started | Authors ➤ Getting Started

Lucca Pessoa 1 Jan 09, 2022
Telegram Bot for updating ongoing matches of Fotmob.com in channel by @AbirHasan2005

Fotmob-Bot A very simple Telegram Bot which will update ongoing matches of Fotmob in a channel. Demo Channel Configs API_ID - Get this from @TeleORG_B

Abir Hasan 22 Oct 21, 2022
A multi-tenant multi-client scalable product categorising demo stack

Better Categories 4All: A multi-tenant multi-client product categorising stack The steps to reproduce training and inference are in the end of this fi

7 Feb 15, 2022
Use CSV files as a Nornir Inventory source with hosts, groups and defaults.

nornir_csv Use CSV files as a Nornir Inventory source with hosts, groups and defaults. This can be used as an equivalent to the Simple Inventory plugi

Matheus Augusto da Silva 2 Aug 13, 2022
This bot will send you an email or notify you via telegram & discord if dolar/lira parity breaks a record.

Dolar Rekor Kırdı Mı? This bot will send you an email or notify you via Telegram & Discord if Dolar/Lira parity breaks a record. Mailgun can be used a

Yiğit Göktuğ Budanur 2 Oct 14, 2021
Tools ini hanya bisa digunakan untuk menyerang website atau http/s

☢️ Tawkun DoS ☢️ Tools ini hanya bisa digunakan untuk menyerang website atau http/s FITUR: [ ☯️ ] Proxy Mode [ 🔥 ] SOCKS Mode | Kadang Eror [ ☢️ ] Ht

Bandhitawkunthi 9 Jul 19, 2022
🐙 Share your Github stats for 2020 on Twitter

Year on Github 🐙 Share your Github stats for 2020 on Twitter. This project contains a small web app that let's you share stats about your Github acti

Johannes Rieke 129 Dec 25, 2022