Proxmox 5.1. I found an older thread addressing this issue. I see these error messages a lot in the Proxmox /var/log/syslog. I am using an NFS storage location. First item is an enhancement request --- could the actual error message please be updated? Consider revising the text string "is not online" to "did not respond to a showmount request"? The simple change would help much with debugging the problem. I ask that the text string be revised because the storage device is indeed online. Something in the Proxmox scripts either times out (2 seconds), does not receive a showmount reply, or something else. I do not suspect a lack of a showmount reply because I can run the showmount command all day and the remote storage device responds. Second item is seeking help to debug this log message. Try as I might I cannot debug the root cause of this error message. The systems are using the standard 8 NFS server threads. Running the nfsstat -r command shows no errors, retrans, or bad calls. Likewise, the ifconfig command shows no dropped packets. Hardware includes 1 Gbps connections and the systems use 10000 rpm RAID SAS drives. I appreciate that the messages are "harmless," but the problem causes a lot of log spew. I see in the referenced thread that the developers do not see this problem in their lab. I will help test if Proxmox developers want data or information. Thanks again.