If using multiple machines, one machine needs to store voicemail, recordings, etc. This machine runs an NFS server, which the others connect to.

First:

• Check an entry exists in /etc/hosts for each client.
• Check /etc/sysconfig/iptables, and check the other machines have access. For example (adjust network and netmask to suit):

  -A INPUT -s 192.168.1.0/24 -j pass

• Run "grep enswitch /etc/passwd", and note the uid and gid. These will be used as the anonuid and anongid below.
• Edit /etc/exports and a line like (adjust network, netmask, anonuid, and anongid to suit):

  /var/lib/enswitch 192.168.1.0/24(rw,all_squash,anonuid=100,anongid=101,async)

Then:

Debian / Ubuntu / Devuan:

• apt-get install nfs-kernel-server

CentOS 8 or Rocky Linux:

• systemctl daemon-reload
• systemctl enable rpcbind.service
• systemctl enable nfs-server.service
• systemctl enable rpc-statd.service
• systemctl start rpcbind.service
• systemctl start nfs-server.service
• systemctl start rpc-statd.service

Other systems using System V init scripts:

• chkconfig rpcbind on
• chkconfig nfs on
• chkconfig nfslock on
• service rpcbind start
• service nfs start
• service nfslock start

Other systems using systemd:

• systemctl daemon-reload
• systemctl enable rpcbind.service
• systemctl enable nfs.service
• systemctl enable nfslock.service
• systemctl start rpcbind.service
• systemctl start nfs.service
• systemctl start nfslock.service