Date: Mon, 16 Sep 1996 11:00:50 +0100 (GMT-1) From: af@biomath.jussieu.fr To: randyd@nconnect.net (Randy) Cc: freebsd-questions@freebsd.org Subject: Re: AMD difficulties Message-ID: <199609161000.LAA05673@garfield.biomath.jussieu.fr> In-Reply-To: <XFMail.960915135539.randyd@nconnect.net> from "Randy" at Sep 15, 96 01:10:18 pm
next in thread | previous in thread | raw e-mail | index | archive | help
Randy wrote / a ecrit:
>
> Greetings,
>
> I seem to be having a great deal of difficulty understanding how to get amd
> set up and running on my network. I'm wondering if someone would be willing
> to help me with the following example:....
>
I'll try to. Some parts of amd remain a bit mysterious to me so I'll
try not to go beyond my understanding of it.
> 2 FBSD machines: named "egyptian" and "arabian"
> egyptian is the 'server'
> I wish to export the '/data' filesystem (mounted on /dev/wd1s1c) to arabian
> ( and potentially other machines later)
>
> I'm confused about what's required in /etc/amd.map entries, and /etc/fstab entri
> es
> to get this to work. I can mount these systems normally with mount.
Ok, so I'll assume that you already have the correct entry in
/etc/exports on egyptian.
If you want to mount the remote filesystem at boot time, you need to
add an entry in arabian's /etc/fstab, such as:
/data egyptian:/data rw,nosuid
^^-- list of options here might vary,
check mount man page.
The drawback with that kind of setup is that if for some reason
egyptian is down when arabian is booted, the boot will hang (I think)
for quite some time when trying to do the mount. My version of FreeBSD
(2.1-stable) doesn't seem to support the "bg" (retry mount in
background) option which might be supported in later releases. Check
the documentation for mount and mount_nfs.
That's what automount (and amd) are for. Well, one of the reasons
anyway.
> Furthermor
> e,
> I don't know if I'm supposed to replace mountd with amd, or if amd requires moun
> td.
No. Amd doesn't replace mountd. Amd like mount are on the "client"
side of things whereas mountd is on the "server" side (it gets the
mount requests from clients -- those requests precisely are issued by
mount and amd). You need to run mountd on any machine that exports
filesystems, not on clients.
> (I have enabled amd in /etc/sysconfig) Do I need amd running on both machines
> or just one??
You need to run amd only on the client machine (arabian).
>
> Could someone please illustrate this example a little?? :)
>
>
Now that's the most difficult part. What you want to do looks to me
like what would be achieved (when using the "standard" automount)
through the use of a direct automount map (automount is what is found
on most commercial Unix systems... amd is its free counterpart).
Although they are supposed to be supported, I have never managed to
make direct maps work using amd. Besides this, I would not make a
direct map for a mount point in the root directory.
You didn't specify where you wanted egyptian:/data mounted on arabian,
so I assumed you wanted it in /data as well.
I suggest the following simple setup:
1) put the following in /etc/sysconfig:
amdflags="-l syslog /Net /etc/amd.net.map"
2) edit /etc/amd.net.map as follows:
/defaults type:=host;fs:=${autodir}/${rhost}/root/;rhost:=${key}
* host!=${key};opts:=rw,nosuid; \
host==${key};type:=link;fs:=/;
3) make /data a link to /Net/egyptian/data
cd /
ln -s /Net/egyptian/data data
Before I get flamed: I know that this oversimplified setup is far from
perfect. I works for me though, and amd is such a headache that I've
not investigated further until now.
Many more elaborate solutions can be used, including the usage of a
"trampoline" directory to add one level of indirection between the
directory where the filesystem is mounted and amd's mount point.
Someone had sent me a very helpful mail about this, unfortunately I
can't find it now.
Hope this helps somewhat anyway.
Good luck,
_Alain_
--
Alain FAUCONNET Ingenieur systeme - System Manager AP-HP/SIM
Public Health 91 bld de l'Hopital 75013 PARIS FRANCE
Medical Computing Research Labs Mail: af@biomath.jussieu.fr
Tel: (+33) 1-40-77-96-19 Fax: (+33) 1-45-86-80-68
I've RTFMed. It says: "Refer to your system administrator"
But... I *am* the system administrator :-]
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199609161000.LAA05673>