[SOLVED] Can't mount NFS/CIFS share (MTU 9000)

[TechHome]

Hi,

i restared my Proxmox host and since then I cannot connect to NFS nor CIFS shares. The state of the storage is "Unknown".
When I open the storage device I get

unable to activate storage 'truenas' - directory '/mnt/pve/truenas' does not exist or is unreachable (500)

. Well it is reachable and every other client can connect to truenas exept this Proxmox host.

smbclient //ip/Proxmox_enc -d 0 -U proxmox%mypassword -c 'echo 1 0'

runs without errors.

 

[TechHome]

Found the issue. MTU rate 9000 was set on the TrueNAS host, while the switch had "Jumbo Frames" disabled somehow.