On Sat, 25 Sept 2021 at 02:04, Terry Barnaby terry1@beam.ltd.uk wrote:
Hi,
I use NFS mount (defaults so V4) /home directories with a simple server over Gigabit Ethernet all running Fedora33. This has been working fine for 25+ years through various Fedora versions. However in the last month or so all of the client computers are getting KDE GUI lockups every few hours that last for around 40 secs. /home is not accessible during this time and it feels/looks to be an NFS lockup issue. There are no "NFS server no responding" or such like messages in either the servers or clients /var/log/messages and the network communications seems fine.
Have there been some changes to NFS recently in the kernel ?
Any idea where to begin to try and debug this ?
Think about what has changed. There is always a possibility of "old age"
hardware problems. I once had a PCNFS system that was having NFS issues while connected to a big server with 100's of PCNFS clients. The vendor's ethernet diagnostics didn't find a problem, and other network services were working. A visual inspection of the network card found visibly heat-damaged components. Replacing the card solved the problem.
With multiple clients having problems, look for ways to check all the upstream gear common to clients with issues: server, ethernet switches, and wiring. I have seen cables develop issues that were found using high-end cable test gear.