lkml.org 
[lkml]   [1996]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Union file system
From
Date

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

\
 
 \ /
  Last update: 2005-03-22 13:38    [W:0.055 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site