recursive exports && linux nfs

recursive exports && linux nfs

[Marc Lehmann]

Hi ;)

I am trying to export the whole filesystem hierarchy on one of my servers
(this includes /fs, which is an automounted directory using autofs).

Now I have two problems:

1) exporting: exportfs does not really exports filesystems that are
   not present when exportfs is being called (some of my filesystems
   are only available temporarily). Also, exportfs of course forces the mount
   of all filesystems that are mountable, which can take considerable time.

2) using: I can do cd /nfs/fs, but the directoy is always empty, and when I
   try to step into a subdirectory I always get "No such file or directory".

I am using linux-2.2.18, nfsv3 + nfs-utils-0.2.1.

Thanks a lot for any insights, even if this means "this is not supported"
;)

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      ---==---(_)__  __ ____  __       Marc Lehmann      +--
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Re: recursive exports && linux nfs

[Pavel Machek]

Hi!

> I am trying to export the whole filesystem hierarchy on one of my servers
> (this includes /fs, which is an automounted directory using autofs).
> 
> Now I have two problems:
> 
> 1) exporting: exportfs does not really exports filesystems that are
>    not present when exportfs is being called (some of my filesystems
>    are only available temporarily). Also, exportfs of course forces the mount
>    of all filesystems that are mountable, which can take considerable time.
> 
> 2) using: I can do cd /nfs/fs, but the directoy is always empty, and when I
>    try to step into a subdirectory I always get "No such file or directory".
> 
> I am using linux-2.2.18, nfsv3 + nfs-utils-0.2.1.
> 
> Thanks a lot for any insights, even if this means "this is not supported"
> ;)

This can't be supported, afaict, because nfs handles have limited
size.

								Pavel
-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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Re: recursive exports && linux nfs

[Marc Lehmann]

On Fri, Dec 15, 2000 at 11:54:46PM +0100, Pavel Machek <pavel@suse.cz> wrote:
> > 2) using: I can do cd /nfs/fs, but the directoy is always empty, and when I
> >    try to step into a subdirectory I always get "No such file or directory".
> > 
> > Thanks a lot for any insights, even if this means "this is not supported"
> > ;)
> 
> This can't be supported, afaict, because nfs handles have limited
> size.

Ehrm, did you really read my mail? Most people told me something like
"recursive exports are not supported" (actually, they are and they work),
and it seems nobody really read what I wrote :(

My problem is that autofs doesn't work. Example:

/	reiserfs
/fs	autofs
/fs/big	ext2

When I exportfs /, /fs AND /fs/big then I can mount /fs on another box,
but it is always empty, even if something (e.g. /fs/big) is mounted and
can be accessed fine the whole time. Automounting doesn't work, either, of
course.

Another (less grave) problem is that exportfs (and/or rpc.nfsd) require
network access and access to the volume, so they a) mount all automounted
directories (VERY expensive) and require network access (making all
clients NOT survive a reboot).

-- 
      -----==-                                             |
      ----==-- _                                           |
      ---==---(_)__  __ ____  __       Marc Lehmann      +--
      --==---/ / _ \/ // /\ \/ /       pcg@opengroup.org |e|
      -=====/_/_//_/\_,_/ /_/\_\       XX11-RIPE         --+
    The choice of a GNU generation                       |
                                                         |
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Re: recursive exports && linux nfs

[Pavel Machek]

Hi!

> > > 2) using: I can do cd /nfs/fs, but the directoy is always empty, and when I
> > >    try to step into a subdirectory I always get "No such file or directory".
> > > 
> > > Thanks a lot for any insights, even if this means "this is not supported"
> > > ;)
> > 
> > This can't be supported, afaict, because nfs handles have limited
> > size.
> 
> Ehrm, did you really read my mail? Most people told me something like
> "recursive exports are not supported" (actually, they are and they work),
> and it seems nobody really read what I wrote :(

They do not work too well. They break guarantee that handles are
persistent across reboots. Recursive exports are huge kludge. They
have to be.

[Sorry, I did not read your mail too carefully]

> My problem is that autofs doesn't work. Example:
> 
> /	reiserfs
> /fs	autofs
> /fs/big	ext2
> 
> When I exportfs /, /fs AND /fs/big then I can mount /fs on another box,
> but it is always empty, even if something (e.g. /fs/big) is mounted and
> can be accessed fine the whole time. Automounting doesn't work, either, of
> course.
> 
> Another (less grave) problem is that exportfs (and/or rpc.nfsd) require
> network access and access to the volume, so they a) mount all automounted
> directories (VERY expensive) and require network access (making all
> clients NOT survive a reboot).
> 

-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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