TCPDUMP question

It seems to work as expected for me, but I did notice one thing. When I first tried to run the program as root, it failed to create the first file with a permission error. It turns out that tcpdump changes uid/gid internally to the user/group tcpdump. Since that user/group did not have write access to the directory, it failed. Once I created a subdir and gave tcpdump ownership of the subdir (chown/chgrp), tcpdump performed as expected.

via TCPDUMP question – FedoraForum.org.

“mount.nfs4: Operation not permitted” when mounting NFS device

This is a configuration issue. A required parameter needs to be added to the file /etc/exports to define the root file system for mounting.

The parameter that needs to be added follows:

fsid=0

An example line would look like the following:

/storage *(rw,fsid=0,sync,insecure_locks,insecure,no_root_squash)

Additional information

NFSv4 works differently and no longer references the root of the file system but instead requires the root to be defined with fsid=0.

If fsid=0 is not present, permission will never be granted for the file system to be mounted.

via RHEL6: “mount.nfs4: Operation not permitted” when mounting NFS device – IBM System Cluster 1350 (1410).

NFS4 is different.   After configuring exportfs the old fashioned way the nfs mounts did not work at all.  I narrowed it down to the CentOS server running nfs4 and then found this article from IBM.  It seems to work now.

CentOS 64 bit bad ELF interpreter

You’re on a 64-bit system, and don’t have 32-bit library support installed.

sudo yum install glibc.i686

via linux – CentOS 64 bit bad ELF interpreter – Stack Overflow.

Also had to yum install gtk2.i686.  Here’s the solution from the above link for  Debian based systems:

Updated: Since it seems this answer is still getting viewed, and occassionally up-voted, note that the solution above works on CentOS, Fedora, or Red Hat derived operating systems; on a Debian or Ubuntu derived system, however, one would instead use

 sudo apt-get install ia32-lib 

For some reason, after all these years of using 64 bit OSs, and still having an active, running FC10 installation, this was the first time I had no choice but to run a 32-bit app on a 64 bit machine.
The above solution worked

CentOS 5 – BIND/named network unreachable resolving issue

Disable the IPV6 in BIND. For CentOS 5.4, edit the /etc/sysconfig/named file and add the following options into the BIND startup

OPTIONS=”-4″

This will cause the BIND server to only resolve or use IPV4 and disable IPV6 support. Save the file and restart BIND server.

via CentOS 5 – BIND/named network unreachable resolving issue | hafizonline.net blog.

This has been going on for months and I finally noticed these errors from named filling up syslog.  The above fix worked and now syslog is quiet again — the way it should be.

VMware Player – Virtual Network Editor

The Virtual Network Editor (vmnetcfg.exe) is not extracted during the installation and it is really needed if you want to mess around with the virtual network settings on the host OS.

It is a problem if you have different network adapters installed, like eg Bluetooth, WiFi, Hamachi etc

Extract cab files

You can extract all files from the installation by using the option /e and a destination folder is supplied

C:\Download\vmware>VMware-player-3.1.3-324285.exe /e .\extract

Change to the subfolder and find the file network.cab, open it in eg Izarch and extract vmnetcfg.exe to the vmware player installation folder. You can also create a shortcut in your list of program files if needed

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via Look sharp | VMware Player – Virtual Network Editor.

This worked.  I didn’t have to install izarch either — 7-zip extracted the .cab files just fine.  I can’t believe vmware didn’t just install the network editor for the player.  What’s up with that?

Red Hat / CentOS: Swap / Change Ethernet Aliases

Red Hat / CentOS: Swap / Change Ethernet Aliases.

This didn’t work the first time I tried it and now it does.  For some reason eth0 and eth1 get switched on the 64bit CentOS 5.7 build which causes routing problems.  This can also be solved by fixing the static routes in /etc/rc.local.  It bothered me to have these interfaces have different names depending on what OS is running.  I think there’s also a way to force this in /etc/udev/ directory by adding a persistent-net rule file.  It all works now.

BTW: I also changed /etc/sysconfig/hwconf but don’t think that had any effect.