Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Programming
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Databases
Mail Systems
openSolaris
Eclipse Documentation
Techotopia.com
Virtuatopia.com
Answertopia.com

How To Guides
Virtualization
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Windows
Problem Solutions
Privacy Policy

  




 

 

Red Hat Enterprise Linux 9 Essentials Book now available.

Purchase a copy of Red Hat Enterprise Linux 9 (RHEL 9) Essentials

Red Hat Enterprise Linux 9 Essentials Print and eBook (PDF) editions contain 34 chapters and 298 pages

Preview Book

10.8.  NFS and rpcbind

Note

The following section only applies to NFSv2 or NFSv3 implementations that require the rpcbind service for backward compatibility.
The rpcbind[2] utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they expect to serve. The client system then contacts rpcbind on the server with a particular RPC program number. The rpcbind service redirects the client to the proper port number so it can communicate with the requested service.
Because RPC-based services rely on rpcbind to make all connections with incoming client requests, rpcbind must be available before any of these services start.
The rpcbind service uses TCP wrappers for access control, and access control rules for rpcbind affect all RPC-based services. Alternatively, it is possible to specify access control rules for each of the NFS RPC daemons. The man pages for rpc.mountd and rpc.statd contain information regarding the precise syntax for these rules.

10.8.1.  Troubleshooting NFS and rpcbind

Because rpcbind[2] provides coordination between RPC services and the port numbers used to communicate with them, it is useful to view the status of current RPC services using rpcbind when troubleshooting. The rpcinfo command shows each RPC-based service with port numbers, an RPC program number, a version number, and an IP protocol type (TCP or UDP).
To make sure the proper NFS RPC-based services are enabled for rpcbind, issue the following command as root:
rpcinfo -p
The following is sample output from this command:
program vers proto   port
100021    1   udp  32774  nlockmgr
100021    3   udp  32774  nlockmgr
100021    4   udp  32774  nlockmgr
100021    1   tcp  34437  nlockmgr
100021    3   tcp  34437  nlockmgr
100021    4   tcp  34437  nlockmgr
100011    1   udp    819  rquotad
100011    2   udp    819  rquotad
100011    1   tcp    822  rquotad
100011    2   tcp    822  rquotad
100003    2   udp   2049  nfs
100003    3   udp   2049  nfs
100003    2   tcp   2049  nfs
100003    3   tcp   2049  nfs
100005    1   udp    836  mountd
100005    1   tcp    839  mountd
100005    2   udp    836  mountd
100005    2   tcp    839  mountd
100005    3   udp    836  mountd
100005    3   tcp    839  mountd
If one of the NFS services does not start up correctly, rpcbind will be unable to map RPC requests from clients for that service to the correct port. In many cases, if NFS is not present in rpcinfo output, restarting NFS causes the service to correctly register with rpcbind and begin working. For instructions on starting NFS, refer to Section 10.5, “Starting and Stopping NFS”.
For more information and a list of options on rpcinfo, refer to its man page.

  
 
  Published under the terms of the Creative Commons License Design by Interspire