Re: / on ramfs, possible?

[sl@whiskey.fireplug.net (Stuart Lynne)]

In article <200010300727.IAA12250@hell.wii.ericsson.net>,
Anders Eriksson <aer-list@mailandnews.com> wrote:
>--==_Exmh_17293564P
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>I want my / to be a ramfs filesystem. I intend to populate it from an 
>initrd image, and then remount / as the ramfs filesystem. Is that at 
>all possible? The way I see it the kernel requires / on a device 
>(major,minor) or nfs.
>
>Am I out of luck using ramfs as /? If it's easy to fix, how do I fix it?

Yes it works.

You will need pivot_root. 

Something like the following at the end of your initrd /linuxrc script 
should mount your ramfs, copy the existing root fs files to it, pivot
and unmount your old root. YMMV
 
    mkdir -p /ramfs /ram1
    mount -t ramfs /ramfs /ramfs
    find / | sed '/^\/ramfs/d;/^\/proc\/.*/d' | cpio -pdmV /ramfs
    cd /ramfs
    pivot_root . ram1
    exec chroot . sh -c 'umount /ram1; exit' < dev/console >dev/console


BTW has anyone thought of writing a small utility to emulate df for ramfs?

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Stuart Lynne <sl@fireplug.net>       www.fireplug.net        604-461-7532
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