Re: Have ext3 on SanDisk CF but can't disable write-back caching as kernel instructs

From: Dan Harkless (usenet_at_harkless.org)
Date: 07/15/03 

Date: 15 Jul 2003 12:25:30 -0700

"pojen" <pojen1@hotmail.com> wrote in message
news:<ber511$82n0t$1@ID-82445.news.uni-berlin.de>:
> I will suggest you to do some research on CF to IDE.

Research on what aspect of it?

> If you use 2.4 kernel,

Yes, we're using the 2.4.20 kernel that SuSE 8.2 comes with, tweaked
to not build modules we don't need.

> hack ide.c is must.

Hack it in what way?

> Then, why not to put most of your system to cramfs and
> read-only and just keep a small piece of the CF to r/w. Even the power lost,
> your system will never lost after boot.
> I used to put my /etc, /var and /tmp on ram disk when system-init and s-link
> to cramfs system. Here is what I did:
> 1. keep a /etc somewhere cramfs and copy it to ramdisk at the boot time.
> 2. cramfs /etc s-link to ramdisk /etc mount point.
> 3. Then, copy your extra setting from r/w(if exist) to overwrite /etc
> setting. If not exist, well, you still have the default one.
> JFFS or JFFS2 can be done on CF but you will need mtd-cf module to simulate
> MTD device(never try).

As I mentioned previously, we're running the root filesystem out of an
initrd ramdisk. It lives on the /boot partition, which we don't
mount, so there's no danger of corrupting it.

The concern is corrupting our read-write data partition (the whole
point of our device is to exchange a bunch of data). 

--
Dan Harkless
usenet@harkless.org
http://harkless.org/dan/

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