Thank you for detailed information,  I would like to use NFS and see how it works. My end goal is to use iSCSI for cinder volume service. 

Do you think switching to NFS v4 will fix the problem in my case. My setup is super simple but somehow it just doesn't like NFS and cinder-volume service is showing down even all the permission and configs are correct. 

On Fri, Mar 1, 2024 at 9:19 AM <smooney@redhat.com> wrote:
On Fri, 2024-03-01 at 09:10 -0500, Satish Patel wrote:
> It Looks like everyone hates NFS and nobody uses it :)
for cidner unless its with a hardware san there are may better options

for better or worse a non 0 numbner of peole decide to put nova's /var/lib/nova/instances directory on NFS shares
instead of using somehting like ceph
>
> On Tue, Feb 27, 2024 at 11:31 PM Satish Patel <satish.txt@gmail.com> wrote:
>
> > Folks,
> >
> > I am configuring NFS for the cinder backend but somehow it doesn't go
> > well. I am running kolla-ansible with the 2023.1 release.
> >
> > cinder.conf
> >
> > [DEFAULT]
> > enabled_backends = volumes-ssd,volumes-nfs
> >
> > [volumes-nfs]
> > volume_driver = cinder.volume.drivers.nfs.NfsDriver
> > volume_backend_name = volumes-nfs
> > nfs_shares_config = /etc/cinder/nfs_shares
> > nfs_snapshot_support = True
> > nas_secure_file_permissions = False
> > nas_secure_file_operations = False
> >
> > Inside the cinder_volume docker container I can see it mounts NFS
> > automatically and directory permissions is also cinder:cinder also I am
> > able to write on NFS share also so it's not a permission issue also.
> >
> > $ docker exec -it cinder_volume mount | grep nfs
> > 192.168.18.245:/volume1/NFS on
> > /var/lib/cinder/mnt/1ec32c051aa5520a1ff679ce879da332 type nfs
> > (rw,relatime,vers=3,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.16
> > 8.18.245,mountvers=3,mountport=892,mountproto=udp,local_lock=none,addr=192.168.18.245)
nfs v3 should not be used with nova instances and when used for cinder voume there are some know bugs or feature partiy
gaps like live extend.
qemu recommends 4.2 as a minium version to mitigate the massive locking issues with v3 and for some other feature such
as spares file support.  nfs is not a bad idea in general, its fine to use with manial but putting block storage on an
NFS share is generally a bad idea so its not a great fit for cinder/novas usage. for services like glance or manila its
fine.

> >
> > But service is still showing down.
> >
> > > cinder-volume    | os-ctrl2@volumes-nfs  | nova | enabled | down  |
> > 2024-02-28T04:13:11.000000 |
> >
> > In logs I am seeing these 3 lines but then no activity in logs even after
> > restarting the container so that is very strange.
> >
> > 2024-02-28 04:13:12.995 153 ERROR os_brick.remotefs.remotefs [None
> > req-6bcb8eab-6aa6-4c36-9a7a-ed673c39dcbc - - - - - -] Failed to mount
> > 192.168.18.245:/volume1/NFS, reason: mount.nfs: Protocol not supported
> > : oslo_concurrency.processutils.ProcessExecutionError: Unexpected error
> > while running command.
> > 2024-02-28 04:13:13.501 153 WARNING cinder.volume.drivers.nfs [None
> > req-6bcb8eab-6aa6-4c36-9a7a-ed673c39dcbc - - - - - -] The NAS file
> > permissions mode will be 666 (allowing other/world read & write access).
> > This is considered an insecure NAS environment. Please see
> > https://docs.openstack.org/cinder/latest/admin/blockstorage-nfs-backend.html
> > for information on a secure NFS configuration.
> > 2024-02-28 04:13:13.501 153 WARNING cinder.volume.drivers.nfs [None
> > req-6bcb8eab-6aa6-4c36-9a7a-ed673c39dcbc - - - - - -] The NAS file
> > operations will be run as root: allowing root level access at the storage
> > backend. This is considered an insecure NAS environment. Please see
> > https://docs.openstack.org/cinder/latest/admin/blockstorage-nfs-backend.html
> > for information on a secure NAS configuration.
> >
> > Has anyone configured NFS and noticed any behavior?
> >
> >
> >
> >