Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 9 Apr 1996 14:30:33 -0400 (EDT) | From | "William E. Roadcap" <> | Subject | Re: Overmounting a filesystem |
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On Tue, 9 Apr 1996, Bryn Paul Arnold Jones wrote:
> On Tue, 9 Apr 1996, William E. Roadcap 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) > > > > > That's not what he ment (i think anyway), you can mount over existing > files, say you had /mnt, with floppy, cdrom, .... in, you can mount > something on /mnt, but you woulden't be able to see the stuff in orignal > directory. ie:
Perhaps that is not what he meant, but (barring the kernel code in the original message) it is what he asked.
The behaviour you describe was discussed on the list a month or two ago. It is common behavior of Unix filesystems to hide the files which exist in directory once you mount a filesystem onto that directory. I find nothing unacceptable about this behaviour, infact is seems quite logical to me.
If you need to mount a filesystem onto a populated directory, then you should create an empty subdirectory there.
> you get the idea, if you had what's variously been called unionfs, ufs, > and ifs (don't ask why, you don't want to know), you can mount multiple > devices on one mount point, and see 'through' the top fs to fs's below. > I don't how it would handle mounting a fs over a populated directory, but > I think it could be made to handle this either way (ie mounting would > either hide the underlieing files, or allow them to show through).
Here again, just create subdirectories under /mnt for these various filesystems. Asking for the kernel to handle this automatically, IMHO, is just plain lazyness and bloat, again IMHO.
Besides, if you setup your /etc/fstab and /mnt hierarchy ahead of time, it's simply a matter of issuing something like
mount /mnt/cdrom or mount /mnt/fd0 etc... __ William E. Roadcap mailto://roadcapw@cfw.com TITUS Software ftp://titus.cfw.com/pub Waynesboro, Va (USA) http://www.cfw.com/~roadcapw
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