NFS Storage content not visible via Web

[rvoelker]

Hopefully I can explain well enough, still a bit new to PVE(which is great, BTW).

Setup summary
Single Node deployment with 3 or 4 qemu VM's

Spoiler: PVE Versions

proxmox-ve: 5.1-42 (running kernel: 4.13.13-6-pve)
pve-manager: 5.1-46 (running version: 5.1-46/ae8241d4)
pve-kernel-4.13: 5.1-42
pve-kernel-4.13.13-6-
pve: 4.13.13-42
pve-kernel-4.13.13-2-pve: 4.13.13-33
corosync: 2.4.2-pve3
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.0-8
libpve-common-perl: 5.0-28
libpve-guest-common-perl: 2.0-14
libpve-http-server-perl: 2.0-8
libpve-storage-perl: 5.0-17
libqb0: 1.0.1-1
lvm2: 2.02.168-pve6
lxc-pve: 2.1.1-3
lxcfs: 2.0.8-2
novnc-pve: 0.6-4
proxmox-widget-toolkit: 1.0-11
pve-cluster: 5.0-20
pve-container: 2.0-19
pve-docs: 5.1-16
pve-firewall: 3.0-5
pve-firmware: 2.0-4
pve-ha-manager: 2.0-5
pve-i18n: 1.0-4
pve-libspice-server1: 0.12.8-3
pve-qemu-kvm: 2.9.1-9
pve-xtermjs: 1.0-2
qemu-server: 5.0-22
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.6-
pve1~bpo9

Have added NFS storage from a Buffalo Terastation NAS (dump, Disk Image, ISO, template, Container, Container Template) primarily to act as backup destination for VMs.

Spoiler: NFS Config

cat /etc/pve/storage.cfg

nfs: TeraStation2_NFS
export /mnt/array1/vm2_backups
path /mnt/pve/nfs_storage
server nfs_server.domain.com
content images,vztmpl,iso,rootdir,backup
maxfiles 1
options vers=3

Problem Summary
Upon fresh installation of PVE and addition of the NFS storage, the content (only backup dumps) is visible using the web admin panel.
√ One can also use the shell to navigate to /mnt/pve/nfs_storage/dump and list the contents of the mount

Within a few days, or maybe after a few scheduled backups have run, the content of the NFS Storage disappears from the web admin.
√ Once the web content no longer shows anything, one can no longer list the contents of the dump directory via the shell - an "ls: reading directory '.' : Input/output error" is returned
√ One CAN navigate to the other directories, such as images or template using the shell
√ One CAN see the content on the NAS when examined directly(NAS is also shared via AFP and SMB)

Other thoughts
There is another server with similar configuration using a different Terastation that continues to work. Only difference I can see is that the other Terastation is a newer model.
Restarting the PVE doesn't bring it back
Restarting the NAS doesn't bring it back
Removing files on the NFS share other than the backup dumps and backup logs (such as .DS_Store created by a Mac connecting to the share) doesn't bring it back

Any thoughts or suggestions about how I can get the content of the NFS Storage to appear in the web admin?

 

[rvoelker]

For those that may run in to the same problem, and to help remind myself if I run in to this issue again, here's what solved it for me.

As it turns out, the NFS storage server (Buffalo TS5600) has two NFS modes: User Mode and Kernel Mode. I had been using "User Mode", but after reading a quote from the manual:

• To use shared folders set for NFS as drives on VMware ESX/ESXi, change the operation mode from “User Mode” (default setting) to “Kernel Mode”.

I decided to give it a try. Problem solved by switching to 'Kernel Mode'. I can now see content via the web admin console on the NFS Storage.

And, FWIW, I am using the default NFS mount options created when adding NFS storage to Proxmox.