[arch-projects] [mkinitcpio PATCH 1/3] /run/initramfs: copy the whole ramfs
Gerardo Exequiel Pozzi
vmlinuz386 at yahoo.com.ar
Thu Nov 17 20:51:37 EST 2011
On 11/17/2011 10:21 PM, Dave Reisner wrote:
> On Fri, Nov 18, 2011 at 11:42:43AM +1100, Tom Gundersen wrote:
>> On Fri, Nov 18, 2011 at 5:23 AM, Thomas Bächler<thomas at archlinux.org> wrote:
>>> Am 17.11.2011 18:07, schrieb Tom Gundersen:
>>>> I see two potential issues: boot speed and memory use. Moving stuff
>>>> around in memory should be pretty much instantaneous, and the memory
>>>> (a couple of MB) will be swapped out quick enough so it shouldn't make
>>>> a difference.
>>>> I'd be happy to write a new patch where this is optional, but I don't
>>>> think we should optimize for stuff unless we know it is a measurable
>>> Depending on what's in there, it could be big. For example, I once wrote
>>> a hook that extracted a tarfile that was stored inside initramfs (that
>>> tarfile was the whole root filesystem IIRC).
>> That's something to take into consideration. I think it would be best
>> if we were able to optimize the cases that need it by adding some
>> exceptions to the copying, but still keep the bits needed for
>> shutdown++, rather than disabling it altogether. Having huge
>> initramfs' being a corner case, any workaround should of course be
>> unintrusive (if that is not possible then I agree on just allowing
>> this stuff to be switched off).
>> [untested: would bindmounting a directory (like say /lib/modules) to
>> itself exclude it from "cp -ax"?]
> No, it won't. Generally, detection of crossing onto another mount is
> done by comparing the devno of '.' to the devno of '..'. Bind mounts
> aren't special in this regard -- they'll just expose the underlying
> physical mount.
Mmm no, you can not access to files in underliying mount from such path.
Anyway the rootfs is the HEAD of vfsmount, so you can not
But supose that you can do a bindmount... -a is used that implies -d,
that implies --preserve=links, in that case cp will fails because will
try to create a link to directory. ;)
Why no just copy the needed files? Yes needs more steps...
>>> Other than that, people WILL complain.
>> Undoubtedly. They always do.
Gerardo Exequiel Pozzi
\cos^2\alpha + \sin^2\alpha = 1
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