Scraps

Bits and pieces I want to be able to grab quickly. This page will change frequently.

Disable power button shutdown

edit /etc/systemd/logind.conf

uncomment HandPowerKey, set to ignore

Get & Set date w/ epoch time

Get from good machine:

date +%s

Set on another:

date -s '@1705865491'

Image and Compress Disk

dd if=/dev/sda bs=100M | pv -ptera -s500G | lz4 > backup-name.dd.lz4

(-s500G refers to the image size, for estimates)

Mount the whole disk image: (have to un-lz4 first ofc)

kpartx -a -v myimage.disk

mount /dev/mapper/loop0p1 /mnt/myimage

Then, to unmount:

umount /mnt/myimage

kpartx -d -v myimage.disk

ntplogtemp

#!/bin/bash
/usr/local/bin/ntplogtemp -o -l /chronyLogs/temps
sed '/ZONE0/d' -i /chronyLogs/temps
sed '/sensor/d' -i /chronyLogs/temps
sed -i 's/LM0/CPU/g' /chronyLogs/temps
sed -i 's/LM1/CPU/g' /chronyLogs/temps

cycle systemd logs

sudo journalctl --rotate ; sudo journalctl --vacuum-time=1s

show systemd logs from boot

sudo journalctl -b

Raspberry Pi

Quick Pi ID

Easy way to get a quick visual indicator to ID a Pi you're remoted into:

Blink pwr LED at 1Hz:

echo timer | sudo tee /sys/class/leds/led1/trigger

Set pwr LED back to monitor voltage:

echo input | sudo tee /sys/class/leds/led1/trigger

Heartbeat LED

set in config.txt

dtparam=act_led_trigger=heartbeat

Grow partition on first boot

Add to the end of /boot/cmdline.txt

quiet init=/usr/lib/raspi-config/init_resize.sh

chronyc tracking

-m flag combines commands. For example: sources -v, tracking, sourcestats -v

chronyc -m 'sources -v' tracking 'sourcestats -v'

DHCP and Static IP on the same interface

Ubuntu Server 20.04, should apply to netplan in general.

network:
  version: 2
  ethernets:
    eno1:
      dhcp4: true
      addresses:
        - 172.16.1.20/22
      gateway4: 172.16.0.1
      nameservers:
        search:
          - syninf.net
        addresses:
          - 172.16.0.2

Find files under certain size and move them

find . -type f -size -150M -exec mv {} ../junk \;

nmap testers

NTP

sudo nmap -sU -p 123 --script ntp-info 172.16.1.6

DHCP

sudo nmap -sU -p 67 --script=dhcp-discover 172.16.0.2

Standalone certbot DNS

sudo certbot certonly --manual --preferred-challenges dns -d webgis.syninf.net

rsync incremental copy

https://www.redhat.com/sysadmin/sync-rsync

sudo rsync -avuP /mnt/data/media/ /mnt/six/media/

Add NTP Server to PiHole DHCP

echo 'dhcp-option=42,172.16.0.2' | sudo tee /etc/dnsmasq.d/42-pihole-dhcp-ntp.conf

Restart pihole

sudo service pihole-FTL reload

Build LinuxPTP on Alpine

Enable community repository

install deps

apk add alpine-sdk linux-headers bsd-compat-headers 
git clone git://git.code.sf.net/p/linuxptp/code linuxptp
make ; make install

Cycle Chrony Logs

#!/bin/bash
# chrony log rotation

cd /var/log/chrony

mv measurements.log measurements.$(date +"%Y%m%d").log
mv statistics.log statistics.$(date +"%Y%m%d").log
mv tracking.log tracking.$(date +"%Y%m%d").log

sync

chronyc cyclelogs

chrony.conf ptp as pps refclock

server time-a.nist.gov
server time-a-wwv.nist.gov

refclock SHM 0 poll 3 refid GPS
refclock PHC /dev/ptp0:extpps:nocrossts:pin=0 width 0.1 refid PHC pps

logdir /var/log/chrony
log statistics tracking measurements

driftfile /var/lib/chrony/chrony.drift

dumpdir /etc/chrony/dump

rtcsync

allow
cmdallow

Proxmox

re-number VM

1) shut down VM 2) rename the storage

zfs rename pool1/vms/vm-112-disk-0 pool1/vms/vm-1001-disk-0

3) rename the configuration file

export vgNAME=vg-images newVMID=173 oldVMID=175 ;  \
sed -i "s/$oldVMID/$newVMID/g" /etc/pve/qemu-server/$oldVMID.conf; mv /etc/pve/qemu-server/$oldVMID.conf /etc/pve/qemu-server/$newVMID.conf; \
unset vgNAME newVMID oldVMID;
scraps.txt · Last modified: 2024/05/17 16:00 by admin
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