Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: Union file system | From | Matthias Urlichs <> | Date | Thu, 28 Nov 1996 18:45:34 +0100 (MET) |
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Hi,
Tuomas Heino wrote: > >> I don't really understand why loopback mounts don't exist in Linux then. >> It really doesn't sound too hard to implement for someone who knows the fs >> code of Linux fairly well. >> >Well some kind of loopback mount exists AND is in the 2.*.* kernels ;) >mount /tmp/fdimage /mnt -o loop=/dev/loop0,blocksize=1024
That is NOT what we all mean when we talk about a loopback mount.
A loopback mount means that, for example, /tmp is also visible as /var/tmp, but _without_ a symlink from one to the other. Great when /www/WHOEVER/bin and /lib needs to be a bunch of identical files for all WHOEVERs, but cannot be symlinked because the servers chroot to /www/WHOEVER...
The "loop" device just makes a single file available as a fake block device. A neat hack, but it's not what we need -- you can probably mount the thing from several places at once, but you can't write to it.
-- Matthias Urlichs \ noris network GmbH / Xlink-POP Nürnberg Schleiermacherstraße 12 \ Linux+Internet / EMail: urlichs@noris.de 90491 Nürnberg (Germany) \ Consulting+Programming+Networking+etc'ing PGP: 1024/4F578875 1B 89 E2 1C 43 EA 80 44 15 D2 29 CF C6 C7 E0 DE Click <A HREF="http://info.noris.de/~smurf/finger">here</A>. 42
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