April 3, 2022

[Note] Chromebook Linux VM

It creates a user.  Change its password:

$ sudo su

# passwd <username>

SSH to Chromebook Linux VM ("CLV" from here for short):

  1. Enable sshd in CLV.
  2. ssh from CLV to another system (e.g. Linux, Mac with SSHD set up) with tunneling.
  3. From linux/mac (or any system with SSHD), ssh to the tunneling port.

$ sudo su

# cd /etc/ssh
# rm sshd_not_meant_to_be_run
# vi /etc/ssh/sshd_config

Define/uncomment these:

Port 2020
AllowAgentForwarding yes
AllowTcpForwarding yes

Restart sshd service:

$ sudo systemctl start ssh
$ sudo systemctl enable ssh

From CLV, ssh to the target machine to establish the tunneling:

$ ssh -f -N -T -R 2020:localhost:2020 <userid>@<target machine>

From the target machine, you can SSH to CLV

$ ssh -p 2020 <CLV username>@localhsot

NOTE: if the Chromebook is on battery, it may go to sleep and break the connection while you're connect to it via SSH.

January 15, 2022


I've been feeling uncomfortable about the current heavily centralized "Web 2.0".  There are definitely benefits and trade-offs.  There are many articles about this, so not going to repeat/list here.  This note contains just a brief summary and pointers.

"Web3", although it's still early, but the concept and the technology are solid and good to experiment now.  It's still too complex for non techie folks, or would anyone really care.  It's very interesting how all these different ideas, concepts and technologies have come together, built, and (will be) used.

  • Web 1.0 - nobody called it "1.0" back then. It was the dawn of the internet for the general public.  People and companies started to build web sites.
  • Web 2.0 - centralized internet. Google, Facebook, Amazon, etc – they own people's data, know about the people more than themselves.
  • Web3 - decentralize data and internet.

There are many hypes and interesting technologies for web3, but these are quite interesting:

I don't feel too strongly about cryptocurrency or NFT, but with metaverse, and for decentralized data/internet, they seem to be good tools and are needed.

I have been thinking about the idea of decentralized data, network, and organization for a while, so I was very excited when I found out about IPFS and DAO. They are not new concepts nor the first attempt to realize the ideas, but this time, it looks pretty good.

I am pretty sure  IPFS, DAO, NFT, and multiverse…all these will look and work very differently in 10 years.  Maybe it will be called something else, and decentralization will be there for sure.  It just needed to be more robust and easier to understand and use.

December 19, 2021

[Note] HEIC

Environment: Ubuntu 20


Photos from iPhone->Google Photo->Download saves as .HEIC, can't view on Linux.


$ sudo apt install heif-gdk-pixbuf

$ sudo apt install libheif-examples

$ heif-convert -q 90 [HEIC file] [filename.jpg]