[clug] NFSv4 "Invalid argument"

[Tessa Jensen]

Check umask settings maybe? - if it's set to default, then any new file
being created by virt-manager in the ISO directory may not have the
read-write permissions that it needs.


On Thu, Oct 16, 2014 at 9:14 PM, Scott Ferguson <
scott.ferguson.clug at gmail.com> wrote:

> Excellent George, thanks for persevering, and especially thanks from
> other with the same problem who will benefit from you posting your results.
>
> Not an ideal situation - using the set v3 method, but it works, which is
> a start.
>
>
> On 16/10/14 21:19, George at Clug wrote:
> >     Scott,
> >
> > I have had some success with the virt-manager and NFS.  The issue
> > seems to be two fold, a) NFS version 4 is more complex and I do not
> > know how to use it, b)  that I was not using the correct option for
> > controlling the version of NFS _and_ in OpenFiler I had to set the NFS
> > share to no_root_squash
> > This site
> > "
> https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Administration_Guide/sect-shared-storage-nfs-migration.html
> "
> > gave me the idea to go and look in OpenFiler to see if I could change
> > the NFS shares (export) options, and I discovered that I could change
> > between the default of root_squash to no_root_squash. (of course
> > no_root_squash is not as secure).
>
> That's one way - another way is to use the anonuid and anongid options.
> 0=root
> I don't know that has any advantages or no_root_squash or the v3 method.
> NOTE: I've used the no_root_squash option on webservers (no virtual
> host) to get around the www-data problem, though this is not something I
> now do.
>
> ------------8<-------------->8---------------------------------
> >
> > I have not resolved the a) issue, but I have the b) option: "-o
> > vers=3"
> > # mount -t nfs -o vers=3 -v
> > 192.168.0.12:/mnt/vg2/vol1/san12_nfs_ds1/kvm-images/images
> > /var/lib/libvirt/images
> >
> > Previously I had used the wrong syntax; "nfsvers=3"
> ------------8<-------------->8---------------------------------
>
> You can chain those o(ptions),should you need to (standard mount format
>  e.g. -o nfsver=3,sec=krb5,etc
>
> For testing I find the -f (fake) and -v (verbose, more v's is more
> verbose) options useful
> e.g.:-
> $ su -c "mount -fvvvt cifs -o credentials=/home/scott/.cifs
> //dev/packages /var/cache/apt/archives"
> Password:
> mount: fstab path: "/etc/fstab"
> mount: mtab path:  "/etc/mtab"
> mount: lock path:  "/etc/mtab~"
> mount: temp path:  "/etc/mtab.tmp"
> mount: UID:        0
> mount: eUID:       0
> mount: spec:  "//dev/packages"
> mount: node:  "/var/cache/apt/archives"
> mount: types: "cifs"
> mount: opts:  "credentials=/home/scott/.cifs"
> mount: external mount: argv[0] = "/sbin/mount.cifs"
> mount: external mount: argv[1] = "//dev/packages"
> mount: external mount: argv[2] = "/var/cache/apt/archives"
> mount: external mount: argv[3] = "-f"
> mount: external mount: argv[4] = "-v"
> mount: external mount: argv[5] = "-o"
> mount: external mount: argv[6] = "rw,credentials=/home/scott/.cifs"
> mount.cifs kernel mount options:
> ip=192.168.0.2,unc=\\dev\packages,user=scott,pass=********
>
> You might use sudo instead. I don't have access to an nfs share from
> where I'm writing - but the effect is the same with nfs. Note that the
> share isn't actually mounted (-f switch). Confusingly dev (development),
> in this instance, is a box name, not a file system.
>
> >
> > Now mounting the NFS share with option "-o vers=3" I can change the
> > permissions on the folders and files, see the below commands which
> > should explain things for you;
> >
> ------------8<-------------->8--------------------------------->
> >
> =====================================================================================
> > Now to put the permissons the way I wanted them
> > --------------------------------------------------
> > # chown -R libvirt-qemu:libvirt-qemu /var/lib/libvirt/images
> > # ls -al  /var/lib/libvirt/images
> ------------8<-------------->8--------------------------------->
> > And now the VM will run without an errors.
> >
> >
> ===================================================================================
> > But I get the below error messages when using virt-manager if I do not
> > use "# chmod -R 777 /var/lib/libvirt/images"
> >
> > "The emulator may not have search permissions for the path
> > '/var/lib/libvirt/images/ISO/debian-7.5.0-amd64-DVD-1.iso'."
>
> Hmmmm. I probably shouldn't suggest this, but an insecure solution,
> might be to modify the group's membership. I'd still try the anonid/gid
> options first - then that share should mount as root.
>
> Can any other readers suggest something?
>
>
> ------------8<-------------->8---------------------------------
>
>
> Kind regards
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