Thanks, Amit, for responding to this query.
There haven't been any changes in the network; the only difference is that we've upgraded glibc.
With the previous version of glibc, NFS was working fine. We were using portmap instead of rpcbind, so rpcbind isn't running now.
In our current system, here are the outputs:
ps aux | grep nfsd
root 9064 0.0 0.0 4052 340 pts/2 S+ 23:48 0:00 grep nfsd
# ps aux | grep rpcbind
root 9231 0.0 0.0 4052 356 pts/2 S+ 23:48 0:00 grep rpcbind
# netstat -tuln | grep 111
udp 0 0 0.0.0.0:30111 0.0.0.0:*
# lsmod | grep nfsd
nfsd 372736 1 - Live 0xffffffffc05f1000
# cat /proc/filesystems | grep nfsd
nodev nfsd
# cat /etc/netconfig
cat: can't open '/etc/netconfig': No such file or directory
# cat /etc/exports --> no data, we are using this command in the startup process of nfsd.
exportfs -i -orw,sync,insecure,no_subtree_check,no_root_squash 172.16.0.0/18:/mnt/raid/data
Just tried to copy netconfig file from libtirpc/doc/netconfig and could see change in these outputs.
# netstat -tuln | grep 111
udp 0 0 0.0.0.0:111 0.0.0.0:* --> portmap is up with udp protocol in 111 port
# cat /etc/netconfig
#
# The network configuration file. This file is currently only used in
# conjunction with the TI-RPC code in the libtirpc library.
#
# Entries consist of:
#
# <network_id> <semantics> <flags> <protofamily> <protoname> \
# <device> <nametoaddr_libs>
#
# The <device> and <nametoaddr_libs> fields are always empty in this
# implementation.
#
udp tpi_clts v inet udp - -
tcp tpi_cots_ord v inet tcp - -
rawip tpi_raw - inet - - -
local tpi_cots_ord - loopback - - -
unix tpi_cots_ord - loopback - - -
But still nfsd is not up.