Catalina: extremely slow traversing NFS based directories from Linux Ubuntu 20.04

• MacOS: Catalina 10.15.7
• Previous Linux server: circa 2010 based Fedora
• New install: Linux Ubuntu 20.04 on the exact same HW
• Network running at 1000mbps.

I recently upgraded a Linux server from a circa 2010 based Fedora to Ubuntu 20.04. With Fedora, no NFS problems at all.

I use Finder to mount nfs shares. However, when traversing the NFS file system, Finder, or /usr/bin/ls, are extremely slow at traversing those NFS directories. For example, it takes 15-20 seconds to display the top level directories, which contained all of 9 directories.

If I use /usr/bin/ls to get a directory listing, I get:

macmini: /Volumes/u2/Pictures > time ls -l

nfs server 192.168.1.21:/u2: lockd not responding

nfs server 192.168.1.21:/u2: lockd alive again

...

real 2m9.13s

user 0m0.00s

sys 0m0.01s

So eventually is will show me the listing, but to take over 2 minutes to display a grand total of 35 directories and files? Somethings not right. When I had Fedora as the server, this completed immediately. So I need to fix this.

An interesting aspect to this is that it seems to be only related traversing directories. I can transfer files at close 1g speeds:

Transfer time of a 2.7gb file:

• • NFS: 98mb/sec transfer speed
  • SFTP; 111gb/sec transfer speed

Not the same, but close enough for now given that I have a bigger fish to fry. With top speed of a 1g network, I should get somewhere between 110-125mb/sec, that's not bad.

I think this has something to do with the locks daemon and the lockd not responding messages being output

Anyone have a solution or an article to read to help resolve this issue? Much appreciated.

Thanks, Jim