trinity-users@lists.pearsoncomputing.net

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Month: September 2015

Re: [trinity-users] Where do I find the most expert nfs help?

From: "Dr. Nikolaus Klepp" <office@...>
Date: Fri, 25 Sep 2015 11:11:29 +0200
Am Freitag, 25. September 2015 schrieb Gene Heskett:
> On Thursday 24 September 2015 12:59:45 Dr. Nikolaus Klepp wrote:
> 
> > Am Donnerstag, 24. September 2015 schrieb Gene Heskett:
> > > On Thursday 24 September 2015 05:32:53 Richard Glock wrote:
> > > > On Thu, 24 Sep 2015 05:18:52 Gene Heskett wrote:
> > > > > On Thursday 24 September 2015 03:03:10 Dr. Nikolaus Klepp wrote:
> > > > > > > > > Subject says it all. I need to find the experts.
> > > > > > > > >
> > > > > > > > > Cheers, Gene Heskett
> > > > > > > >
> > > > > > > >  I use my local Linux User Group, full service.
> > > > > > >
> > > > > > > My local linux user group. Chuckle. I am 1 of a group of 3. 
> > > > > > > Not too many linux users in these here parts.  I am quite
> > > > > > > likely 100 miles from the nearest "user group" that numbers
> > > > > > > 10 or more.
> > > > > > >
> > > > > > > > I use nfs on my local network, it just works so I am far
> > > > > > > > from an expert. I export my "/home/<user>" dir and
> > > > > > > > manually mount , cli, on the clients.
> > > > > > > >
> > > > > > > > Debian stable.
> > > > > > >
> > > > > > > Debian Wheezy.  With TDE.
> > > > > > >
> > > > > > > Cheers, Gene Heskett
> > > > > >
> > > > > > Hi Gene!
> > > > > >
> > > > > > I dropped NFS on linux ages ago, due to simillar issues as you
> > > > > > describe. Now I use SSHFS and haven't had any issues since
> > > > > > then. So, what about using SSHFS instead of NFS?
> > > > > >
> > > > > > Nik
> > > > >
> > > > > Never heard of it till now.  So I installed it, along with
> > > > > sshmenu which pulled in a dozen other rubyish packages.
> > > > >
> > > > > Silly Q though, does mc understand sshfs?  Or do I need to find
> > > > > a new 2 pane file manager that does understand it?
> > > > >
> > > > > One thing's for sure, NFS, even V4 is old enough to have bit
> > > > > rot.
> > > > >
> > > > > Thanks Nik.  Off to read some man pages.
> > > > >
> > > > > Cheers, Gene Heskett
> > > >
> > > > On the MC command line, do cd fish://user_name@machine_name
> > >
> > > Resource temporarily unavailable, fish might not be installed?
> > >
> > > But a "cd /sshnet/shop", after using Niks's example sshfs command, a
> > > mount point I created, then chown'd to me, works just fine.  Since I
> > > also have an ssh -Y session into each of those machines, if I need
> > > to muck around out of my home dir, sudo is always available.
> > >
> > > To summerize, I added these lines to /etc/fstab:
> > > shop.coyote.den:/  /sshnet/shop    fuse.sshfs  defaults,idmap=user 
> > > 0  0 lathe.coyote.den:/ /sshnet/lathe   fuse.sshfs 
> > > defaults,idmap=user  0  0 GO704.coyote.den:/ /sshnet/GO704  
> > > fuse.sshfs  defaults,idmap=user  0  0
> > >
> > > Which I suspect can be nuked. but there it is.  The mount points
> > > were created and chown'd to me.
> > >
> > > Now I will see if the fstab entries are surplus by doing the same
> > > thing to each of the other 3 machines currently alive on this local
> > > network. Then I can hopefully reach across the net from any machine
> > > to any machine, which was my target in the first place.
> > >
> > > According to my results of doing the mkdir yadda, followed by the
> > > sshfs login, it works just fine on GO704. I can look at /home/gene
> > > on this machine from the ssh -Y session into that machine.  Two more
> > > machines to go...  But first, clean up the mess in my fstab.
> > >
> > > Oh, and sshmenu is broken, needs a ruby dependency the deb didn't
> > > list. I don't have a heck of a lot of ruby stuffs in use here.  I'll
> > > nuke it.
> > >
> > > Nik's example sshfs command line was then executed once for each of
> > > the mount points.
> > >
> > > Humm, on GO704 it all works, and here it all works BUT the sshfs
> > > session converts the individual subdir used from gene:gene to
> > > root:root. If thats permanent it will be a problem.
> > >
> > > So I go over to the ssh -Y session into the lathe and do the mkdir
> > > tapdance again.  But while it will connect to both this machine and
> > > GO704, it will not connect to "shop", "connection reset by peer", so
> > > once again that shop machine is being a spoiled brat.
> > >
> > > Doing that same tapdance on machine "shop" works as expected.
> > > Now why can't lathe access shop?
> > >
> > > gene@lathe:~$ sshfs gene@shop:/ /sshnet/shop
> > > read: Connection reset by peer
> > >
> > > However, gcode written for the lathe (only a 2 axis machine) is not
> > > usable on shop or GO704 which are 4 axis milling machines, so that
> > > is not a showstopper loss.  Besides, I can go to the other machine
> > > and do the file copies if I need it bad enough.
> > >
> > > What does bother me though is that if the ownership
> > > of /sshnet/machinename being changed to root is permanent, that will
> > > mean I have to do the "sudo chown -R /sshnet" dance on 4 machines
> > > when they have been rebooted.  That is the only way I know to get
> > > around the target machines asking me for a non-existent root pw.
> > >
> > > > NFS these days is a hairball of epic proportions. Try getting the
> > > > NFS daemons to bind to a specific address per the man pages...
> > >
> > > And has been so for at least 5 years, the level of neglect seems
> > > rampant. The manpages haven't been touched in 9 years.
> > >
> > > But till now I have used it if I could because there wasn't a usable
> > > alternative. I long ago got tired of the constant perms fixing that
> > > CIFS needs, too many roots in the M$ world.
> > >
> > > > RG
> > >
> > > Many many thanks to both Nik and Richard for supplying the clues and
> > > examples that made it work .  And to Timothy for pointing out that
> > > it might be a problem with rpcbind.  But yesterdays huge update
> > > included rpcbind, which all machines have now been updated, and that
> > > did not fix nfs.
> > >
> > > Cheers, Gene Heskett
> >
> > Hi Gene!
> >
> > Plese check that the file /etc/ssh/sshd_config is identical for all 3
> > maschines.
> >
> It is not.  GO704 and shop have this line in that file:
> 
> HostKey /etc/ssh/ssh_host_ecdsa_key
> 
> While lathe and coyote do not.  And I have no clue if that key is 
> available on those 2 machines
> 
> > On rebooting: you could add the "sshfs ..." lines to /etc/rc.local:
> >
> > su - gene -c "sshfs gene@shop:/ /sshnet/shop"
> >
> And this bypasses the pw request for my pw from each machine as its 
> called to duty?
> > .. then you sould have the user of the remote files set to "gene".
> >
> > Also check that the subfolders of /sshnet/* are owned by "gene" when
> > no filesystem is mounted there.
> >
> > Nik
> 
> Thank you Nik.
> 
> Cheers, Gene Heskett

Hi Gene!

Ok, this is the workflow you need to go through for each maschine - all steps, including new key generation etc.
Plese make sure, that you do not use any passphrase, or you'll need to enter it each time you use sshfs:

# walk-the-shop, round 1: recreate SSH-keys for all maschines
	rm ~/.ssh
	ssh-keygen

# round 2: distribute ssh public keys, you'll need this for all 3 maschines, not just the other 2:
	ssh-copy-id -i ~/.ssh/*.pub gene@this_one
	ssh-copy-id -i ~/.ssh/*.pub gene@the_other
	ssh-copy-id -i ~/.ssh/*.pub gene@the_next_one

# round 3: check, if you can log into any of these maschines without password:
	ssh gene@this_one
	ssh gene@the_other
	ssh gene@the_next_one

# round 4: reboot, try round 3 again for all maschines.

# round 5: try mounting sshfs for all 3 maschines:
	sudo bash
	su - gene -c "sshfs gene@shop:/ /sshnet/shop"
	su - gene -c "sshfs gene@shop:/ /sshnet/coyote"
	su - gene -c "sshfs gene@shop:/ /sshnet/lath"

# round 6: add the lines above to /etc/rc.local, reboot and check if it worked

Now, does this procedure fail anywhere? 
If yes, what linux versions are running where? 

Nik

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