I was curious about what exactly time is going to NFS file metadata when client writes a file. My assumption is that client time is recorded and not NFS server's time. But I wasn't able to find out about it in the RFC, and cannot test it at a time. Please advise. Thank you.
The time on the system where the nfs client will mark the utime change using it's time, and then it is cached. At some point, the client will update the server with new times and these are based on the client. I'm sure we can all come up with weird timestamps that can come up in the event that time sync is significant.
Moral of the story: Use NTP. Alot.
Check out part III a. here: http://www.time-travellers.org/shane/papers/NFS_considered_harmful.html