Hi, we are trying to migrate a storage and authentication server with NFS and NIS from Debian 6 to Ubuntu 20.4. The hostname, domain name and IP address of the new server was retained as that of old server. The partitions are ext4 in new while it was xfs in old server. For some reason clients are unable to mount NFS partitions and so not able to login with NIS users since their home folders are in NFS partition. Is ext4 fine to work as an NFS partition? Or any changes need to be done in client side? And whether size of partitions matter while mounting NFS? Please help.

ext4 should work fine for NFS.
What errors are showing in the NFS logs on the server and when you manually mount from a client.
Did the new server default to NFSv4?

Hi

Yes ext4 works fine, which mount options did you use in your exports file and for mounting on your client?