Linked by Thom Holwerda on Mon 30th Jan 2012 20:39 UTC
General Unix Finally something really interesting to talk about. If you've used UNIX or any of its derivatives, you've probably wondered why there's /bin, /sbin, /usr/bin, /usr/sbin in the file system. You may even have a rationalisation for the existence of each and every one of these directories. The thing is, though - all these rationalisations were thought up after these directories were created. As it turns out, the real reasoning is pretty damn straightforward.
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RE[3]: why not / instead of /usr
by phoenix on Tue 31st Jan 2012 17:59 UTC in reply to "RE[2]: why not / instead of /usr"
Member since:

"It would make more sense to move everything from /usr to /, then the other direction.

The idea is that you can snapshot /usr seperately from /var, /etc, /boot, etc.

If /boot, /var, /home, and /usr are separate filesystems, then it means that / is also a separate filesystem. Why would snapshotting one filesystem be easier than snapshotting another filesystem? And why wouldn't you want to snapshot the application configuration files along with the applications (meaning, /etc along with apps under /)?

Reply Parent Score: 2

Lennie Member since:

No, this is for when there is just one filesystem (partition is to technical for most users ? and the technical users always get the sizes wrong ?)

With btrfs for example you can snapshot directories.

So for example when you do distribution updates/upgrades and do automatic snapshotting of the binaries in /usr.

There could be data in /var you don't want to undo when you restore the binaries.

Something like that ? Anyway, Fedore has a plan. Have a look at the site: "The merged directory /usr, containing almost the entire vendor-supplied operating system resources, offers us a number of new features regarding OS snapshotting and options for enterprise environments for network sharing or running multiple guests on one host. Most of this is much harder to accomplish, or even impossible, with the current arbitrary split of tools across multiple directories."

Reply Parent Score: 3

phoenix Member since:

Yeah, it may be impossible to do with the current split. But moving things to /usr instead of leaving them in / is just wrong.

I've read through the mailing list threads, the wiki articles etc. And all of their reasoning for moving to /usr applies just as well to moving to /.

Reply Parent Score: 2