This hampers nfs usability, for example:
$ fsysopts ./ /hurd/nfs [...] $ cp -a /bin/true ./ cp: failed to preserve authorship for `./true': Operation not supported $ ./true $ /lib/ld.so /bin/true $ /lib/ld.so $PWD/true [...]/true: error while loading shared libraries: [...]/true: failed to map segment from shared object: Error 1073741869
IRC, freenode, #hurd, 2012-03-14:
<civodul> i just realized that ld.so uses mmap unconditionally <civodul> so executables or shared libs can't be used off a netfs-based file system <civodul> that's annoying <tschwinge> civodul: Do you know what it takes to fix libnetfs? I have no idea. <tschwinge> Never looked at it. <civodul> tschwinge: implementing io_map <civodul> but i think the idea is that io_map typically isn't convenient for network file systems <civodul> which is why it doesn't have it <civodul> the GCS says "thou shall not require mmap" ;-)
http://lists.gnu.org/archive/html/bug-hurd/2001-10/msg00306.html. Analysis to be found on mmap page.