2010/1/25 Chris Simmonds <chris@xxxxxxxxxx>: > Johnny Hung wrote: >> >> 2010/1/22 Marco Stornelli <marco.stornelli@xxxxxxxxx>: >>> >>> 2010/1/22 Johnny Hung <johnny.hacking@xxxxxxxxx>: >>>> >>>> 2010/1/20 Marco Stornelli <marco.stornelli@xxxxxxxxx>: >>>>> >>>>> 2010/1/20 Johnny Hung <johnny.hacking@xxxxxxxxx>: >>>>>> >>>>>> 2010/1/19 Matthias Kaehlcke <matthias@xxxxxxxxxxxx>: >>>>>>> >>>>>>> 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 >> > I got it. The rootfs contains at least /etc directory, /etc/inittab, /etc/fstab. Bysybox will read /etc/fstab to mount etc to rootfs's etc from other partition. Okay, it's reasonable. Another query, how to do it in many Linux dist as Macro mentioned, use initramfs ? I am sure I can arrange / to /dev/hda1 and /etc to /dev/hda2. Thank you so much BRs, H. Johnny > You have two /etc directories: one in the the read-only root file system and > one in the jffs2 fs. In the root fs you have /etc/fstab, /etc/inittab and > any scripts it may call. The init program will mount /dev/mtdblock5 over the > top of the /etc that is in the rootfs, so giving you the read/write version > of /etc. Any files open in the old /etc - e.g. /etc/inittab - will continue > to be open, but any new files opened in /etc will use the read/write version > in jffs2. You can also do some interesting things with symbolic links... > This technique works. I have used it in several projects. > > -- > Chris Simmonds 2net Limited > chris@xxxxxxxxxx http://www.2net.co.uk/ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-embedded" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ