≡ Menu

computer network

HowTo: Speedup ping and traceroute Command Responses under Linux / Unix

The following question was asked in the Unix networking exam:

     How do you speed up ping and traceroute command responses under Unix or Linux operating systems?

How can I speed up my ping or traceroute commands on a Linux?
[click to continue…]

Sysadmin because even developers need heroes!!!

Explain: Five Nines ( 99.999% ) Computer / Network Uptime Concept

Q. Some service provider guarantees 99.999% uptime for their service. Can you explain meaning of five nines?
[click to continue…]

Linux NFS Export / share directory to other UNIX / Linux computer

Q. I’m using CentOS 5 Linux 64 bit version. How do I share directory called /data2 to all other UNIX / Linux computers?

A. NFS (Network file system) is both a protocol and file system for accessing and sharing file systems across a computer network using UNIX and Linux. NFS v4 is used in modern Linux distributions. It offers performance improvements, mandates strong security, and introduces a stateful protocol etc.

How do I export a directory with NFS?

In order to export or share directory called /data2, you need to edit a file called /etc/exports. The file /etc/exports serves as the access control list for file systems which may be exported to NFS clients.:
# vi /etc/exports
Add config directive as follows:
/data2 *(rw,sync)

Each line contains an export point and a whitespace-separated list of clients allowed to mount the file system at that point. Each listed client may be immediately followed by a parenthesized, comma-separated list of export options for that client.


  • rw – Allow both read and write requests on /data2 NFS volume
  • sync – Reply to requests only after the changes have been committed to stable storage

Save and close the file. Restart the nfs service:
# /etc/init.d/nfs restart

NFS client configuration

Client computer need to mount file system using mount command or /etc/fstab file, enter:
# mkdir /mnt/nfs
# mount -t nfs4 nfsserver-name-or-ip:/data2 /mnt/nfs

Read the man page for more configuration options:
$ man exports