Re: [gentoo-user] NFS tutorial for the brain dead sysadmin?

[Tom H <tomh0665@gmail.com>]

On Sat, Jul 26, 2014 at 9:51 AM, Alan McKinnon <alan.mckinnon@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 ]

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