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Em Wednesday 03 August 2011, Dan Williams escreveu: > On Wed, 2011-08-03 at 10:29 +0200, Michał Górny wrote: > > Hello, > > > > AFAIK NetworkManager is the most common tool which keeps writing > > to /etc/resolv.conf file during runtime. Such a solution makes it hard > > to support configurations where rootfs in read-only most of the time. > > > > That's why I'm considering moving the resolv.conf file to /var. I'm not > > sure about the exact location there but /var seems much better for > > non-static resolver configs. > > > > I think that the best solution would be to patch glibc so it will first > > try to load 'dynamic' resolv.conf from /var, and then fallback to > > static configs in /etc. > > > > I'd really appreciate any kind of feedback on that idea. > > Having resolv.conf in /etc also prevents read-only root, thus /var is > actually a better place for it since it's really a composite of various > information and can change at will. Lennart wrote a blog post a month > or so ago about moving it somewhere, I forget where, but you might read > that post as well. I'll take a patch that allows you to pass > --with-resolv-conf-file-path=<whatever> which shouldn't be too hard to > do. > > I don't know how far you're likely to get with glibc though, > since /etc/resolv.conf is standardized in various places and it's a > long-standing tradition. The best way to make changes here is simply to > try out patches in your distro and see how it works, and perhaps > eventually they'll see which way the wind is blowing.
This problem is not specific to NM, any dhcp client will have to rewrite /etc/resolv.conf to update name server's IP addresses. When I create read-only filesystems I prefer to create a symbolic link (/etc/resolv.conf in this case) pointing to the real file in the read/write media or ramdisk. Another alternative is use a read-only /etc at first, mounting a ramdisk in /etc and populating the ramdisk with the some contents of the read-only /etc. The latter is a little tricky to make work right because for some instants /etc will be empty.
-- Lamarque V. Souza http://www.geographicguide.com/brazil.htm Linux User #57137 - http://counter.li.org/ http://planetkde.org/pt-br |