Messages in this thread | | | From | "Jeff Voskamp [MFCF]" <> | Subject | Re: Overmounting a filesystem | Date | Tue, 9 Apr 1996 16:46:31 -0400 (EDT) |
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>On Tue, 9 Apr 1996, H. Peter Anvin wrote: >> > On 9 Apr 1996, H. Peter Anvin wrote: >> > >> > > Currently it seems Linux does not permit overmounting a filesystem >> > > (mounting a filesystem on top of another, on the same path). >> > >> > Just tried it, and it works: >> > >> > /dev/hda1 on / type ext2 (rw) >> > /dev/hda2 on /home type ext2 (rw) >> > /proc on /proc type proc (rw) >> > /dev/hda3 on /home/eddie type ext2 (rw) >> > >> >> Try mounting /dev/hda3 on /home, on top of /dev/hda2 instead. That's >> what I'm talking about. > >Ok, I tried that and the attempt was rejected. I still think that is the >logical think for Linux to do. > >Why would you want to do such a thing anyway? If you need a filesystem >mounted onto another, make a subdirectory for that filesystem. Mounting a >filesystem in a populated directory hides the existing files anyway, how >do you benefit?
Design a "overlay" filesystem.
If you attempt to read a file that exists in the overlay you get the overlay. If it doesn't exist you get the file beneath. When writing to a file, it gets created in the overlay. Appends get a bit hairy sometimes.
Combine that with the loop filesystem and you have a neat way of handling multiple kernel source configurations - mount the machine specific stuff on top of /usr/src/linux.
Or mount the hard drive over a live portion on the CDROM - it will eventually tell you all the files you beat on locally. Also
>...
>IMHO, this all seems to boil down to laziness.
Nope, just wanting to do strange things.
>Please convince me otherwise, I very well may have tunnel vision on this >subject.
Hopefully this gives you a few ideas.
Jeff Voskamp
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