On Thu, 2011-04-07 at 15:29 -0600, Michael Coffman wrote: > On Thu, Apr 7, 2011 at 8:56 AM, Ian Kent <ra...@themaw.net> wrote: > On Wed, 2011-04-06 at 12:52 -0600, Michael Coffman wrote: > > Hello, > > > > I am trying to use the -host map for global access to > servers in my > > environment. > > > > I have noted on this list that after the first mount of a > server via > > host mapping, the server is never again probed for mount > points. This > > seems like a major flaw in the host map functionality. > This is a > > problem when adding new file systems to our NFS servers. > It means > > systems have to be completely idled in order to get them to > unmount > > and re-mount the servers to see the new mount points (not > possible > > very often in my environment). > > > > Is the assumption that if you use host mapping, your server > will > > either never change, or you have the ability to 'reboot' > your > > environment when a new file system is added to a server? > > > Neither. > > The problem is that exports can be nested and frequently are > (think of > the nohide export option). > > For example, with exports like: > > /export/vol1/data1 > /export/vol1/data2 > > and then add: > > /export/vol1 > > and update the map when either or both /export/vol1/data1 > and /export/vol1/data2 are mounted, /export/vol1 is accessed > it will > cover these mounts. Now that might not seem like a problem but > when you > end up with multiple layers of mounts mounted multiple times > everything > starts to get confused really fast. > > > > First off, thanks for the reply and the details on the reasoning for > not automatically re-scanning servers that have been mounted via host > mapping. > > I guess in my simple world I would never export a higher level > directory if sub-directories were already exported. Do lots or > people really nest exports to the same sets of client systems? I will > have to think about some scenarios and some possibilities of > algorithms on how to deal with them and get back with you... > > In any case, it seems having a way to ping autofs and have it re-read > would imply that the admin would have some knowledge of what was being > requested. > > > > > > > Is there any way that functionality could be added that > would allow > > for sending a signal ( say USR2 ) that would cause the > automounter to > > re-run /etc/auto.net to re-query -host managed servers for > new file > > systems? > > > Well, if you have sensible, realistic, workable ideas on how > to handle > the nesting problem then share. And I don't mean "just do > this ...." > type through away comments that have no workable basis in > fact. > > > Hopefully this will not come across as me saying 'just do it' :) We > have used AMD for years and I would really like to switch to autofs > and was planning on doing so until this issue came up. I believe > that some kind of knob that could be used to refresh the maps on my > clients so they see new exports when added to the servers would be > very useful. Not an automatic re-querying of the servers, but a > signal that I can bump automount with when I know what changes have > been made on the other end and want to refresh.
I'll think more about it. Perhaps, if I can work out some way to check for active mount within nested set of exports, I could ignore the nested ones on update. The problem then will be people complaining that "suddenly it stopped seeing new mounts when I added them". > > Thanks again for taking the time to reply to my message. > > > > Ian > > > > > > -- > -MichaelC _______________________________________________ autofs mailing list autofs@linux.kernel.org http://linux.kernel.org/mailman/listinfo/autofs
