Hi Théo,

Théo Maxime Tyburn 写道：
> I figured out where the problem came from. I forgot to use the 
> -p option
> while copying the store with cp.

I think this will probably work (I mean—it obviously did, but also 
longer-term).

However, ‘cp -p’ does not preserve everything, including hard 
links.  Applications shouldn't care but you might be surprised at 
how much disc space hard links save on my system:

~ λ du -hs /gnu/store
86G	/gnu/store
~ λ du -hs --count-links /gnu/store
192G	/gnu/store

I was!

‘cp -a’ should preserve hard links but I personally recommend 
using rsync instead, with a paranoid helping of -aHAX flags. 
Unlike cp, it's resumable, which is nice when copying 100s of 
gigabytes.

Kind regards,

T G-R