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On Wed, Mar 18, 2015 at 2:12 PM, Dale <rdalek1967@×××××.com> wrote: |
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> |
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> I thought there was a tool that just lists the contents. Things is, I'm |
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> not sure what I would be looking at. |
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An initramfs is just a root filesystem. init is /sbin/init unless the |
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kernel is told otherwise. |
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If you took your entire root filesystem, compressed it into a cpio |
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archive, and put that in grub as your initramfs, then your entire |
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distro would run from a ramdisk and you might not even notice the |
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difference (well, assuming you had enough RAM). |
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The only real "magic" with an initramfs is that it mounts your real |
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root somewhere, then swaps it out for the real root: |
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http://manpages.courier-mta.org/htmlman8/switch_root.8.html |
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This is a bit like chroot, but the old root filesystem is deleted in |
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the process (so that your initramfs does not consume any RAM once the |
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system actually boots). I'm not sure exactly how dracut does it with |
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systemd, since my understanding is that during shutdown systemd |
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actually pivots back to the initramfs (which allows all filesystems to |
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be cleanly unmounted instead of merely being mounted read-only). |
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|
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-- |
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Rich |
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