Technology Insights

Test NFS From OSX

When setting up a NFS server its nice to be able to test from your desktop to verify things are working properly. In the current scenario I setup NFS on a BackTrack Linux server and needed to test it quickly from OSX to make sure NFS mounts were advertising properly. Below are a couple quick commands to first display the available NFS mounts and second to mount the NFS drive on OSX to verify functionality.

Technology Errors

invoke-rc.d: initscript nfs-kernel-server, action “start” failed

Earlier this morning I needed to run some tests against a NFS server running on BackTrack Linux version 5 release 3 and ran into some issues installing the nfs-kernel-server. It appeared as if things started to install properly but then the nfs-kernel-server did not start properly and ended up displaying a couple errors. Below I describe the error in more detail followed by the process I used to get the nfs-kernel-server installed properly on BT5.

Information Security

SELinux prevented ruby from reading files stored on a NFS filesytem

While working on a server farm for a client I kept running into some issues with one of the servers. The issue appeared to be a single CentOS Linux server in a cluster of ten CentOS Linux servers configured exactly the same as the other nine CentOS Linux servers was having issues writing to a network storage device. Initially I figured that the CentOS Linux server having the issues had some permission issues with the directory that was mounted to the SAN (Storage Area Network) however after minimal troubleshooting it was verified that the permissions were identical to the other servers. I started looking through other logs on the server having the issue and located some SELinux errors that were noticeably related to the issue at hand. Below I describe where the SELinux error was located, what the specific errors were, and how I was able to resolve the errors on this specific CentOS Linux server.

Technology Errors

Error: Missing dependency: is needed by package nfs-utils

When performing a “yum update” I received the following error which deals with a library needed by the nfs-utils package on CentOS.

Error: Missing dependency: is needed by package nfs-utils

On this machine NFS is not needed so I took the following steps to complete the “yum update”.

  1. Remove nfs-utils: First remove nfs-utils by issuing the below command.
  2. bash

    1. yum remove nfs-utils