Jakob Boghdady jakoberpf

rsync commands

Basics

rsync -avzh <source> <username>@<ip>:<destination>

Advanced

exclude files/dirs based on patterns

redirect traffic incoming on a specific port to a different IP address / another server

`2.2.2.2:4000 -> 1.1.1.1:3000`

Solution

iptables -t nat -A PREROUTING -p tcp --dport 4000 -j DNAT --to-destination 1.1.1.1:3000
iptables -t nat -A POSTROUTING -p tcp -d 2.2.2.2 --dport 4000 -j SNAT --to-source 1.1.1.1
iptables -t nat -A POSTROUTING -j MASQUERADE

iptables cheatsheet

Show iptables rules

This will show the now current state of iptables

iptables -S

This will show all current iptable rules

[manual] create ceph filesystem

Configure MDS (MetaData Server) on a Node which you'd like to set MDS. It sets to [node01] on this exmaple.

ceph-deploy mds create node01

Create at least 2 RADOS pools on MDS Node and activate MetaData Server. For pg_num which is specified at the end of a creating command, refer to official document and decide appropriate value. Documentation

[troubleshooting] macOS M1 minikube network issue

When starting minikube, we see a docker network related error.

Issue

$ minikube start
😄  minikube v1.24.0 auf Darwin 12.0.1 (arm64)
✨  Automatically selected the docker driver

[manual] ceph client setup

Cheatsheet for setting up a new ceph client

Gather key and config

From any autheticated ceph host/client.

root@ceph:~$ ceph auth get-or-create client.fs

[manual] create erasure-coding ceph filesystem pool

Cheatsheet how to setup a erasure coding pool, add it to a ceph filesystem and configure files/directories to use the ec pool.

root@ceph:~$ ceph osd erasure-code-profile set ec-62-profile k=6 m=2 crush-failure-domain=osd crush-device-class=hdd
root@ceph:~$ ceph osd pool create glacier_data_ec-62 erasure ec-62-profile
root@ceph:~$ ceph osd pool set glacier_data_ec-62 allow_ec_overwrites true
root@ceph:~$ ceph osd pool application enable glacier_data_ec-62 cephfs
root@ceph:~$ ceph fs add_data_pool glacier glacier_data_ec-62

	echo ATTENTION: THIS IS UNSAFE!

	echo Which namespace would you like me to terminate\?

	read NAMESPACE_TO_DESTROY

	echo I will terminate namespace $NAMESPACE_TO_DESTROY\!
	(
	kubectl proxy &
	kubectl get namespace $NAMESPACE_TO_DESTROY -o json \|jq '.spec = {"finalizers":[]}' >temp.json

	#!/bin/bash

	# insert/update hosts entry
	ip_address="192.168.x.x"
	host_name="my.hostname.example.com"
	# find existing instances in the host file and save the line numbers
	matches_in_hosts="$(grep -n $host_name /etc/hosts \| cut -f1 -d:)"
	host_entry="${ip_address} ${host_name}"

	echo "Please enter your password if requested."