Author Archives: Kaven Gagnon

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About Kaven Gagnon

System & Network Architect

Linux : How to create a dummy file

Here is a quick how to create a dummy file for a specific size under Linux/Unix : dd if=/dev/zero of=<file_name> bs=<size_in_bytes> count=1 So assuming you want to create a file named “100mb.bin” having 100 Mb size : dd if=/dev/zero of=100mb.bin bs=104857600 count=1

OpenVPN : service failed to start due to unresolved dependencies: set([‘bridge’])

If you setup OpenVPN to be in bridge (layer2) mode instead using NAT/routing (layer3) and then restart the server to make the change effective, you probably noticed the following error message on the Status Overview page repeatedly : service failed to start due to unresolved dependencies: set([‘bridge’]) This is because there is no existing bridge… Read More »

Linux : How to create a bridge interface on RHEL/CentOS

A bridge interface is actually a virtual interface handled by a config file on your Linux system. Creating a bridge is quite simple, just follow those steps and you’re all set! 1. Create the bridge interface configuration file : vi /etc/sysconfig/network-scripts/ifcfg-br0 Add the the following parameters : DEVICE=br0 TYPE=Bridge BOOTPROTO=static ONBOOT=yes STP=on IPADDR= NETMASK= GATEWAY=… Read More »

Qmail : Create a catch-all account with vpopmail

On the latest vpopmail release, there is a bug with the Web interface that prevent creating a catch all mail account for non-existent recipients. When pressing the catch-all button, a blank page is returned. Here is the steps to create the catch-all manually instead of using the WebUI. This example assume that your domain name… Read More »

Linux : How to install source rpm on RHEL/CentOS

Here is a quick tutorial regarding how to install a source RPM on RHEL/CentOS Linux. 1. Prepare the build environment and get the dependencies. Do those following command under your root home directory : yum install rpm-build redhat-rpm-config gcc make mkdir -p ~/rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS} 2. Put the source rpm file at the root of your home directory… Read More »

Bind : validating : dlv.isc.org SOA: got insecure response; parent indicates it should be secure

Have you notified this error message in the logs since bind-9.8.2 update? named: validating @0x7fc170001550: dlv.isc.org SOA: got insecure response; parent indicates it should be secure named: error (insecurity proof failed) resolving ‘dlv.isc.org/DLV/IN’: 0.0.0.0#53 This is related to the new DNSSEC feature which is now enabled by default. This might indicate the DNS resolvers/forwarders you… Read More »