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
$ magik convert [.HEIC file] [filename.jpg]

December 12, 2021

[Note] Ubuntu VirtualBox + VirtualBox Extension Pack


Ubuntu 20.04, VirtualBox 6.1.30 r148432

VBox was updated multiple times.



sudo apt install fails to install VBox Extension Pack 


$ sudo apt install virtualbox-ext-pack

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 10.6 kB of archives.
After this operation, 142 kB of additional disk space will be used.
Get:1 http://us.archive.ubuntu.com/ubuntu focal-updates/multiverse amd64 virtualbox-ext-pack all 6.1.26-2~ubuntu1.20.04.1 [10.6 kB]


Progress state: NS_ERROR_FAILURE
VBoxManage: error: Failed to install "/usr/share/virtualbox-ext-pack/Oracle_VM_VirtualBox_Extension_Pack-6.1.26.vbox-extpack"
VBoxManage: error: VBoxExtPackRegister returned VERR_VERSION_MISMATCH, pReg=0000000000000000 ErrInfo='Helper version mismatch - expected 0x3 got 0x30000'
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component ExtPackManagerWrap, interface IExtPackManager
VBoxManage: error: Context: "RTEXITCODE handleExtPack(Ha
ndlerArg*)" at line 1424 of file VBoxManageMisc.cpp
Installation error: License key incorrect or unknown problem during installation.
dpkg: error processing package virtualbox-ext-pack (--configure):
 installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)


  1. Make sure all VMs are closed.
  2. Open http://download.virtualbox.org/virtualbox/6.1.30/
  3. (firefox was used) Click on Oracle_VM_VirtualBox_Extension_Pack-6.1.30.vbox-extpack
  4. It'll ask to open with Oracle VM VirtualBox - click Ok.
  5. Check: open VBox Manager -> File -> Preferences -> Extensions