* Make changes to read-only file system using RAM
@ 2004-12-21 18:08 Chris Swanson
2004-12-21 18:15 ` Brad Fitzpatrick
0 siblings, 1 reply; 6+ messages in thread
From: Chris Swanson @ 2004-12-21 18:08 UTC (permalink / raw)
To: linux-kernel
Hi,
Has anyone seen any work done on a RAM based file system that
stores only changes to what would otherwise have been a read-only file
system? For example, live Linux CD's rely on RAM file systems to
store directories/files that must be modified, but the majority of the
system is mounted read-only on the CD. I was thinking it would be
really nice if we could mount a read-only medium (like a CD) in
read-write mode, and store only modifications in RAM. This could give
the illusion of a true read-write medium, and the RAM file system
would just grow as more changes are made.
I have searched around a bit and found nothing like this.
Unfortunately, I have no kernel programming experience (although I'd
love to learn). I was wondering if anyone has tried something similar
in the past. Also, if anyone with more experience can see any reason
why this is impossible or impractical, I would love to hear it, before
I come to the same conclusion many months down the line.
Thanks for your time,
Chris
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Make changes to read-only file system using RAM
2004-12-21 18:08 Make changes to read-only file system using RAM Chris Swanson
@ 2004-12-21 18:15 ` Brad Fitzpatrick
2004-12-21 21:05 ` Gergely Tamas
2004-12-22 2:24 ` Phil Lougher
0 siblings, 2 replies; 6+ messages in thread
From: Brad Fitzpatrick @ 2004-12-21 18:15 UTC (permalink / raw)
To: Chris Swanson; +Cc: linux-kernel
Chris,
Check out unionfs.
On Tue, 21 Dec 2004, Chris Swanson wrote:
> Hi,
>
> Has anyone seen any work done on a RAM based file system that
> stores only changes to what would otherwise have been a read-only file
> system? For example, live Linux CD's rely on RAM file systems to
> store directories/files that must be modified, but the majority of the
> system is mounted read-only on the CD. I was thinking it would be
> really nice if we could mount a read-only medium (like a CD) in
> read-write mode, and store only modifications in RAM. This could give
> the illusion of a true read-write medium, and the RAM file system
> would just grow as more changes are made.
> I have searched around a bit and found nothing like this.
> Unfortunately, I have no kernel programming experience (although I'd
> love to learn). I was wondering if anyone has tried something similar
> in the past. Also, if anyone with more experience can see any reason
> why this is impossible or impractical, I would love to hear it, before
> I come to the same conclusion many months down the line.
>
> Thanks for your time,
> Chris
> -
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>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Make changes to read-only file system using RAM
2004-12-21 18:15 ` Brad Fitzpatrick
@ 2004-12-21 21:05 ` Gergely Tamas
2004-12-22 2:24 ` Phil Lougher
1 sibling, 0 replies; 6+ messages in thread
From: Gergely Tamas @ 2004-12-21 21:05 UTC (permalink / raw)
To: Brad Fitzpatrick; +Cc: Chris Swanson, linux-kernel
Hi!
> Check out unionfs.
Did you find a unionfs version for 2.6 ? As far as I see, version 1.0.3 [1]
is only for 2.4 .
For 2.6 one can try for example cowloop [2] (which works nice, btw).
[1] http://www.fsl.cs.sunysb.edu/project-unionfs.html
[2] www.atconsultancy.nl/cowloop
Gergely
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Make changes to read-only file system using RAM
2004-12-21 18:15 ` Brad Fitzpatrick
2004-12-21 21:05 ` Gergely Tamas
@ 2004-12-22 2:24 ` Phil Lougher
2004-12-22 2:27 ` Phil Lougher
1 sibling, 1 reply; 6+ messages in thread
From: Phil Lougher @ 2004-12-22 2:24 UTC (permalink / raw)
To: Brad Fitzpatrick; +Cc: Chris Swanson, linux-kernel
On Tue, 21 Dec 2004 10:15:41 -0800 (PST), Brad Fitzpatrick
<brad@danga.com> wrote:
> Chris,
>
> Check out unionfs.
You could try 'mini_fo'. This is similar to unionfs and it is already
used on a number of liveCDs. Documentation
http://www.denx.de/PDF/Diplomabeit-MK-1.0-net.pdf, software
ftp://ftp.denx.de/pub/mini_fo.
Unfortunately it also only works on 2.4.
Phillip
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Make changes to read-only file system using RAM
2004-12-22 2:24 ` Phil Lougher
@ 2004-12-22 2:27 ` Phil Lougher
2004-12-22 8:37 ` Chris Swanson
0 siblings, 1 reply; 6+ messages in thread
From: Phil Lougher @ 2004-12-22 2:27 UTC (permalink / raw)
To: Brad Fitzpatrick; +Cc: Chris Swanson, linux-kernel
Sorry documentation link broken, it should be
http://www.denx.de/PDF/Diplomarbeit-MK-1.0-net.pdf.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Make changes to read-only file system using RAM
2004-12-22 2:27 ` Phil Lougher
@ 2004-12-22 8:37 ` Chris Swanson
0 siblings, 0 replies; 6+ messages in thread
From: Chris Swanson @ 2004-12-22 8:37 UTC (permalink / raw)
To: linux-kernel; +Cc: Brad Fitzpatrick, Phil Lougher
Thanks to everyone for the info/advice. I will look into these suggestions.
Happy holidays,
Chris
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2004-12-22 8:37 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2004-12-21 18:08 Make changes to read-only file system using RAM Chris Swanson
2004-12-21 18:15 ` Brad Fitzpatrick
2004-12-21 21:05 ` Gergely Tamas
2004-12-22 2:24 ` Phil Lougher
2004-12-22 2:27 ` Phil Lougher
2004-12-22 8:37 ` Chris Swanson
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