tcpdump-examples

Linux high IOwait is a common Linux performance issue. Today we will look at what iowait means and what contributes to this problem. Hope this can give you more ideas about high IOwait issue.

What is IOwait?

IO wait is related to the CPU resource on the server.

The iowait column on top command output shows the percentage of time that the processor was waiting for I/O to complete. It indicates that the system is waiting on disk or network IO. Because the system is waiting on those resources, it can not fully utilize the CPU.

Learn more about what IOwait here.

nealfennimore

# ------------------------------------------------
# Config files are located in /etc/wireguard/wg0
# ------------------------------------------------

# ---------- Server Config ----------
[Interface]
Address = 10.10.0.1/24 # IPV4 CIDR 
Address = fd86:ea04:1111::1/64 # IPV6 CIDR 
PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE; ip6tables -A FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # Add forwarding when VPN is started
PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE; ip6tables -D FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -D POSTROUTING -o eth0 -j MASQUERADE # Remove forwarding when VPN is shutdown

mqu

Report disk usage for gitlab (omnibus installation) into influx database.

• it will report report registry and git size in Mo.
• data will be available at "telegraf/size/[registry,git]

provided files :

• /etc/sudo.d/telegraf : need to run sudo du external command
• /etc/telegraf/telegraf.d/inputs.exec-disk-usage.conf : main script managed by telegraf ; need to restart telegraf
• /etc/telegraf/telegraf.d/scripts/exec-disk-usage is the script computing disk usage and reporting to telegraf computed size in influx format.

lizthegrey

default['sshd']['sshd_config']['AuthenticationMethods'] = 'publickey,keyboard-interactive:pam'
default['sshd']['sshd_config']['ChallengeResponseAuthentication'] = 'yes'
default['sshd']['sshd_config']['PasswordAuthentication'] = 'no'

0x3333

RAM
---
vm-1                      = 1,024 MiB
vm-2                      = 2,048 MiB

Total: 3,072 MiB

CPU(s)
------

staaldraad

# Gawk version
# Remote
grep -v "rem_address" /proc/net/tcp  | awk  '{x=strtonum("0x"substr($3,index($3,":")-2,2)); for (i=5; i>0; i-=2) x = x"."strtonum("0x"substr($3,i,2))}{print x":"strtonum("0x"substr($3,index($3,":")+1,4))}'

# Local
grep -v "rem_address" /proc/net/tcp | awk  '{x=strtonum("0x"substr($2,index($2,":")-2,2)); for (i=5; i>0; i-=2) x = x"."strtonum("0x"substr($2,i,2))}{print x":"strtonum("0x"substr($2,index($2,":")+1,4))}'

# No Gawk
# Local
grep -v "rem_address" /proc/net/tcp  | awk 'function hextodec(str,ret,n,i,k,c){

ropnop

args = "-c" & " -l " & """DISPLAY=:0 terminator"""
WScript.CreateObject("Shell.Application").ShellExecute "bash", args, "", "open", 0

heiswayi

First Method

Deleting the .git folder may cause problems in our git repository. If we want to delete all of our commits history, but keep the code in its current state, try this:

# Check out to a temporary branch:
git checkout --orphan TEMP_BRANCH

# Add all the files:
git add -A

JoshCheek

Why I chose Fish over Bash for students

I'm currently the lead instructor at Code Platoon and an instructor/developer at the Turing School of Software and Design.

I've been advocating the Fish shell and when the choice is up to me, I choose that for my students. Enough people ask about the decision, particularly in relation to the preinstalled Bash shell, that I figured it's worth laying out my reasoning.

TL;DR

paulgambill

/**
 * Retrieves all the rows in the active spreadsheet that contain data and logs the
 * values for each row.
 * For more information on using the Spreadsheet API, see
 * https://developers.google.com/apps-script/service_spreadsheet
 */
function readRows() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var rows = sheet.getDataRange();
  var numRows = rows.getNumRows();