mount ramdisk rootfs /etc directory to jffs2 filesystem.

[Johnny Hung]

2010/1/22 Marco Stornelli <marco.stornelli at gmail.com>:
> 2010/1/22 Johnny Hung <johnny.hacking at gmail.com>:
>> 2010/1/20 Marco Stornelli <marco.stornelli at gmail.com>:
>>> 2010/1/20 Johnny Hung <johnny.hacking at gmail.com>:
>>>> 2010/1/19 Matthias Kaehlcke <matthias at kaehlcke.net>:
>>>>> El Tue, Jan 19, 2010 at 02:17:22PM +0100 Ricard Wanderlof ha dit:
>>>>>
>>>> I consider to use ramdisk as rootfs because worry about wrong
>>>> operation in rootfs (is use jffs2 rootfs) and it will cause system
>>>> boot up failed.
>>>> Another query, does the syslogd/klogd log files also store in jffs2
>>>> rootfs? Write to jffs2 frequently will reduce flash life cycle.
>>>>
>>>> BRs, H. Johnny
>>>>>
>>>>> --
>>>
>>
>> It seems there are a lot of file-systems I have to study :P. The same
>> question is
>> how to split my rootfs? Re-mount /etc, /var to another file-sysyem mtd part when
>> system boot up?
>>
>
Yes, I know. So if I want set etc directoyr to /dev/mtd5 not in rootfs
/, I need to add "/dev/mtdblock5  /etc        jffs2   defaults
0       0" in /etc/fstab file but rootfs doesn't contain /etc
directory because /etc directoyr is store in /dev/mtdblock5.
Do you know what I mean? The kernel execute /sbin/init after mount
rootfs and /sbin/init is link to busybox, busybox will read
/etc/inittab file to initial. The problem is coming, how busybox to
read /etc in rootfs before mount /dev/mtdblock5 to /etc? There is no
program to mount /dev/mtdblock5 to /etc before busybox init execute.

I think I must mistake some concept, please give me a hint.
Thank you
BRs, H. Johnny

> Simply, you can mount each mount point with the fstab file and a
> script, same approach of every linux distribution, nothing more. Even
> in the pc world you can mount your /home on a partition with ext3,
> /var in a partition with ext4, and so on. A very simple approach to
> setup the system, it is to start with NFS for example with "whole" fs,
> copy what you need in the right place, setup the start-up script and
> reboot.
>
> Marco
>