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Upgrade my Lenovo LinuxMint Cinnamon from 20.3 to 21
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4th-December-2022
Shanghai, Rainy, 7-11 celsius degree
Writing on Lenovo ideaPad 710S (LinuxMint) ssh to sdf.org, with
tmux & Vim
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In July this year, LinuxMint team release the Cinnamon 21 "Venessa"
version, my Lenovo ideaPad 710S was running on 20.3 at that moment,
I wantted to taste the latest stuff, but worried about may messing
up the old installation, neither do I want to erase everything to
do a new installation and adding back my personal data and
softwares. They mentioned there will be soon later a instruction to
be released to help live upgrading from 20.3 to 21.

The instructions was released actually very soon after, in August.
I didn't have time to sit down in front of my ideaPad 710S--since I
was almost travelling to mountains for 2 months.

Now I have time to play with it!


##  Preparation
----------------

The upgrade is quite straightforward, It will remind you for all
preparation work. But just be aware that you need to backup your
important data first, don't know where are they? no problem! the
TimeShift software can do this for you, and the mintupgrade
software will check and remind you to do so.
So, there is really nothing you need to worry, "mintupgrade" will
do this anyway for you. :)


##  Updating
-------------

1. Install the upgrade software: mintupgrade
"apt update"
"apt install mintupgrade"

2. Start the mintupgrade
"sudo mintupgrade"
Before you start later work, the tool will ask you do a TimeShift
backup, if you don't have sufficient space in your hard drive or
main SSD, you can use external USB key etc.. 
This is a must do, for your safe.

3. Check 3rd party software package 
mintupgrade will check your 3rd party source and compatibility,
they may advice you roll back to a compatible version or you may
eventually have to remove by yourself otherwise the upgrade may not
continue. 
But you should always check here, whether your 3rd party software
is ok to work in Linux Mint 21, or, you may end up with not working
software that you use daily, in such case you may stay no upgrade.
If they report issue and you believe no impact to you, you could
manually remove those software. 

4. Upgrade
After all above checking, removing work, you will enter into the
upgrade process.
As 21 has dropped some software or lib in 20.3, It will ask you to
confirm that it can remove them, once you confirm, it will proceed,
and then will automatically upgrade and install the new softwares.


## reboot and clean up
-----------------------

After succsessfully upgrade, it will report you all done good.
You are ok to use the system after reboot.

You could now remove the mintupgrade software tool:
"apt remove mintupgrade"

Then reboot:
"sudo reboot"

Once logged into new 21 release, you can also do a clean up by:
"sudo apt autoremove" 

And, you could use "software manager" to re-install the removed
software in 20.3 or install it from other source.


## worked on my Lenovo ideaPad 710S LinuxMint Cinnamon 20.3 to 21
------------------------------------------------------------------

This worked well on my ideapad 710S, with 20.3 and some own 3rd
party software, like Typora and KiCAD.

I kept the Typora software but de-selected the source as
mintupgrade reports not able to find its host.
I removed the KiCAD as I installed it from 3rd party source, and
re-installed it back in Software Manager.

Both above two software works well in Cinnamon 21 Venessa release.

I record this notes for my later revisit if needed.
And I would be happey if someone new to LinuxMint find this
useful!

-Peter