Patrick schrieb: > Patrick schrieb: >> Patrick schrieb: >>> Flemming Madsen schrieb: >>> >>>> Patrick wrote: >>>> >>>>> But isnt there another way? e.g. copying / mount-moving/binding >>>>> real_root to the union or something like that? >>>>> >>>>> >>>> The way i make access to the underlying filesystems is to 'mount -o >>>> move' the underlying >>>> mount point into the union berfore i chroot into it. >>>> >>>> In my setup i have in the flash: >>>> >>>> - A squashfs root filesystem to boot on >>>> - A ram filesyatem to pickup writes >>>> - A /flash to persist things >>>> - The /flash/root directory for patching the squashfs root >>>> >>>> I have these in /mnt and move them into the union to have access to >>>> the >>>> underlying >>>> filesystems after the chroot >>>> >>>> Sketchy: Eg. (with unionfs) >>>> >>>> mount /mnt/ram/ >>>> mount /mnt/flash/ >>>> mount / /mnt/initroot -o bind >>>> >>>> mount -t unionfs unionfs /mnt/union -o >>>> dirs=/mnt/ram:/mnt/flash/root=ro:/mnt/initroot=ro >>>> >>>> mount /mnt/flash /mnt/union/mnt/flash -o move >>>> mount /mnt/ram /mnt/union/mnt/ram -o move >>>> mount /mnt/initroot /mnt/union/mnt/initroot -o move >>>> >>>> cd /mnt/union >>>> chroot . init # Rock & roll >>>> >>> Heh, thats what I exactly tried myself .. but here it doesnt work . >>> none of the mounted filesystems that were moved are accessable / >>> viewable in the union later on. >>> >>> >> heh okay, got that one fixed (added some sleep's and seen it was a >> typo tho.. now my question is .. your /mnt/ram is tmpfs I guess while >> /mnt/flash is where? like where is it actually stored? (only thing I >> can imagine is onto the rootfs) >> > Hmm .. well I think I was wrong with that assumption .. seems as if > your /flash is on another partition/device than the rootfs is .. > otherwise it wouldnt work, would it since the rootfs is mounted ro .. > enlighten me please! >
Finally ... I reconfirmed my statement, that /flash cant be within the actual rootfs .. (tried a loop device tho, and aufs moans about overlapping) .. now I used a dedicated partition .. so it is like: /new is a tmpfs and /real_root is the real rootfs .. now /flash is on another partition and I mount the unionfs like mount -w -t aufs -o dirs=/new=rw:/flash=ro:/real_root=ro aufs /union .. so when changing something on the unified FS changes go to /new obviously .. and if I put for instance /etc/fstab into /flash .. I can have persistent changes. But that is not exactly what I wanted, so I thought of a method having the rootfs under /flash too (so I can easily change files without copying them + their appropiate dirs to /flash) .. Thus I introduced another directory calld /change .. moved it to the unified fs (same with /real_root) and now my init of initramfs looks like: mkdir -p /real_root mkdir -p /new mkdir -p /change mkdir -p /flash mount -w -t aufs -o dirs=/new=rw:/flash=ro:/real_root=ro none /union mkdir -p /union/mnt/new mkdir -p /union/mnt/real_root mkdir -p /union/mnt/flash mkdir -p /union/mnt/change mount -o move /new ${rootmnt}/mnt/new mount -o move /real_root ${rootmnt}/mnt/real_root mount -o move /flash ${rootmnt}/mnt/flash mount -w -t aufs -o dirs=${rootmnt}/mnt/flash=rw:${rootmnt}/mnt/real_root=ro aufs /change mount -o move /change ${rootmnt}/mnt/change Now to explain that: Once I want a persistent change ... I easily adapt the files in /mnt/change .. so the changes go to /mnt/flash .. while /mnt/flash is in hierachy higher than /real_root .. the changes are persistent ... I hope this may help other users who run in a similar kind of problem :-) regards, Patrick > regards, > Patrick > >>> regards, >>> Patrick >>> >>>> ------------------------------------------------------------------------- >>>> >>>> Take Surveys. Earn Cash. Influence the Future of IT >>>> Join SourceForge.net's Techsay panel and you'll get the chance to >>>> share your >>>> opinions on IT & business topics through brief surveys-and earn cash >>>> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >>>> >>>> >>>> >>> >>> >>> ------------------------------------------------------------------------- >>> >>> Take Surveys. Earn Cash. Influence the Future of IT >>> Join SourceForge.net's Techsay panel and you'll get the chance to >>> share your >>> opinions on IT & business topics through brief surveys-and earn cash >>> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV >>> >>> >>> >> >> > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV