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MLEvD

Member

Registered: 2021-02-14

Posts: 141  

to what extent can /usr/share actually be shared?

I have dabbled with systems sharing their /usr/share/icons directory, this is safe and all three had the same versions of icons installed.

What would happen if I tried to get LMDE 4 Debbie and a Minted Beowulf sharing the same /usr/share directory?

What about sharing the entire /usr directory? To what extent can the systems differ, or must they be packageclones of each other?

devujan

Member

Registered: 2019-10-26

Posts: 22  

Re: to what extent can /usr/share actually be shared?

Imho you can share /usr - in ro mode - if you never ever come to the point and do updates. apt can't handle this. If you are creative and like playing - you can try overlay file systems to overcome that to a certain point where complexity breaks you neck.
In non systemd systems it is practically possible to share [ro]  /usr between identical machines, which are painstakingly kept synchronized concerning their package configuration. (We used to run SunOS servers ("clusters")  this way in another century.)
Just do it - and see what happens!
For the systems with the [ro] /usr - you will need to find a way to fool apt. (snapshot && overlay && throw away -> actual updated /usr from mount - would be my first guess - but maybe there is a simpler solution? Maybe you can do it all with translucent logical volume caches?)

MLEvD

Member

Registered: 2021-02-14

Posts: 141  

Re: to what extent can /usr/share actually be shared?

Just do it - and see what happens!

I'm thinking this might be easier in this case because the systems will be on the same box so won't be live at the same time.
To test what might go wrong, I will just grab one system, image the /usr partition, apply updates, reimage the non-updated /usr, then boot up and see if there are complaints.

Ultimately my plan was maybe to host things like icons, themes, and backgrounds, on the network, but maybe there would be sync issues here if trying to share entire /usr/share dir?

angstrom

Member

Registered: 2021-05-02

Posts: 4  

Re: to what extent can /usr/share actually be shared?

What about sharing the entire /usr directory? To what extent can the systems differ, or must they be packageclones of each other?

I wouldn't do it, at least not with /usr, and especially not with two different distributions.

On my setup, I have an ad hoc partition /data that is shared by two distributions, but of course, neither of the two distributions touches this directory.