Hi, I hope this mailing list is the right place to discuss some problems with nfs4.1. Switching from FreeBSD host as NFS server to a Proxmox environment also serving NFS I see some strange issues in combination with VMWare ESXi. After first thinking it works fine, I started to realize that there are problems with ESXi datastores on NFS4.1 when trying to import VMs (OVF). Importing ESXi OVF VM Templates fails nearly every time with a ESXi error message "postNFCData failed: Not Found". With NFS3 it is working fine. NFS server is running on a Proxmox host: root@sepp-sto-01:~# hostnamectl Static hostname: sepp-sto-01 Icon name: computer-server Chassis: server Machine ID: 028da2386e514db19a3793d876fadf12 Boot ID: c5130c8524c64bc38994f6cdd170d9fd Operating System: Debian GNU/Linux 11 (bullseye) Kernel: Linux 5.13.19-4-pve Architecture: x86-64 File system is ZFS, but also tried it with others and it is the same behaivour. ESXi version 7.2U3 ESXi vmkernel.log: 2022-04-19T17:46:38.933Z cpu0:262261)cswitch: L2Sec_EnforcePortCompliance:209: [nsx@6876 comp="nsx-esx" subcomp="vswitch"]client vmk1 requested promiscuous mode on port 0x4000010, disallowed by vswitch policy 2022-04-19T17:46:40.897Z cpu10:266351 opID=936118c3)World: 12075: VC opID esxui-d6ab-f678 maps to vmkernel opID 936118c3 2022-04-19T17:46:40.897Z cpu10:266351 opID=936118c3)WARNING: NFS41: NFS41FileDoCloseFile:3128: file handle close on obj 0x4303fce02850 failed: Stale file handle 2022-04-19T17:46:40.897Z cpu10:266351 opID=936118c3)WARNING: NFS41: NFS41FileOpCloseFile:3718: NFS41FileCloseFile failed: Stale file handle 2022-04-19T17:46:41.164Z cpu4:266351 opID=936118c3)WARNING: NFS41: NFS41FileDoCloseFile:3128: file handle close on obj 0x4303fcdaa000 failed: Stale file handle 2022-04-19T17:46:41.164Z cpu4:266351 opID=936118c3)WARNING: NFS41: NFS41FileOpCloseFile:3718: NFS41FileCloseFile failed: Stale file handle 2022-04-19T17:47:25.166Z cpu18:262376)ScsiVmas: 1074: Inquiry for VPD page 00 to device mpx.vmhba32:C0:T0:L0 failed with error Not supported 2022-04-19T17:47:25.167Z cpu18:262375)StorageDevice: 7059: End path evaluation for device mpx.vmhba32:C0:T0:L0 2022-04-19T17:47:30.645Z cpu4:264565 opID=9529ace7)World: 12075: VC opID esxui-6787-f694 maps to vmkernel opID 9529ace7 2022-04-19T17:47:30.645Z cpu4:264565 opID=9529ace7)VmMemXfer: vm 264565: 2465: Evicting VM with path:/vmfs/volumes/9f10677f-697882ed-0000-000000000000/test-ovf/test-ovf.vmx 2022-04-19T17:47:30.645Z cpu4:264565 opID=9529ace7)VmMemXfer: 209: Creating crypto hash 2022-04-19T17:47:30.645Z cpu4:264565 opID=9529ace7)VmMemXfer: vm 264565: 2479: Could not find MemXferFS region for /vmfs/volumes/9f10677f-697882ed-0000-000000000000/test-ovf/test-ovf.vmx 2022-04-19T17:47:30.693Z cpu4:264565 opID=9529ace7)VmMemXfer: vm 264565: 2465: Evicting VM with path:/vmfs/volumes/9f10677f-697882ed-0000-000000000000/test-ovf/test-ovf.vmx 2022-04-19T17:47:30.693Z cpu4:264565 opID=9529ace7)VmMemXfer: 209: Creating crypto hash 2022-04-19T17:47:30.693Z cpu4:264565 opID=9529ace7)VmMemXfer: vm 264565: 2479: Could not find MemXferFS region for /vmfs/volumes/9f10677f-697882ed-0000-000000000000/test-ovf/test-ovf.vmx tcpdump taken on the esxi with filter on the nfs server ip ca be found here: https://file.io/rtFeuFGlYY98 I tried to analyze, but have no idea what exactly the problem is. Maybe it is some issue with the VMWare implementation? Would be nice if someone with better NFS knowledge could have a look on the traces. Best regards, cd