On Sat, Jul 26, 2014 at 9:51 AM, Alan McKinnon <alan.mckin...@gmail.com> wrote:
>
> NFS uses RPC to do some heavy lifting - I don't know how familiar you
> are with this, so here's the quick version:
>
> When you mount something locally, and need to use the mounted
> filesystem, kernel calls are used to get at the data. This works easily
> as the source disk is local and the kernel can get to it. With NFS, the
> source disk is remote and it's the remote kernel that must do the
> accessing. RPC is a way to safely ask a remote kernel to do something
> and get a result that behaves identical to a local kernel call.
> Obviously, this is rather hard to implement correctly.
>
> The original RPC was written by Sun and other newer implementations
> exist, like libtirpc - to support useful features like not being stuck
> with only UDP. That's what the "ti" means - Transport Independant.
>
> RPC has been in a state of flux for some time and I too have run into
> init-script oddities as things change.
>
> In my case, I have nfs-utils-1.3.0, and rc-update configuredd to start
> rpc.statd. This works because
>
> depend() {
> ...
> need portmap
> ...
> }
>
> and in the init.d file for rpcbind:
>
> depend() {
> ...
> provide portmap
> }
>
> So rpcbind starts at boot time and all my nfs mounts JustWork
To confirm the above, for nfs-utils-1.2.9-r3.
If I start nfs manually, all the associated daemons start too even
though I haven't added them to "default" (although idmapd is started
because of "/etc/conf.d/nfs"):
# ls -1 /etc/init.d/rpc*
/etc/init.d/rpc.idmapd
/etc/init.d/rpc.pipefs
/etc/init.d/rpc.statd
/etc/init.d/rpcbind
# rc-update | grep rpc
# rc-service nfs start
* Starting rpcbind ... [ ok ]
* Starting NFS statd ... [ ok ]
* Setting up RPC pipefs ... [ ok ]
* Starting idmapd ... [ ok ]
* Mounting nfsd filesystem in /proc ... [ ok ]
* Exporting NFS directories ... [ ok ]
* Starting NFS mountd ... [ ok ]
* Starting NFS daemon ... [ ok ]
* Starting NFS smnotify ... [ ok ]
#
