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Private Networks and Bind 9.9.0+

As of BIND 9.9.0 bind is now compliant with RFC6303. RFC6303 addresses the issue that everywhere on the Internet private networks are leaking [People - you need egress firewalls..., egress firewalls, not just ingress]. Name servers receive many queries for addresses that are 'private' [see RFC1918].

Installation & Initialization of PostGIS

Distribution: CentOS 6.x / RHEL 6.x

If you already have a current version of PostgreSQL server installed on your server from the PGDG repository you should skip these first two steps.

XFS, inodes, & imaxpct

Attempting to create a file on a large XFS filesystem - and it fails with an exception indicating insufficient space! There is available blocks - df says so. HUh? While, unlike traditional UNIX filesystems, XFS doesn't suffer from the boring old issue of "inode exhaustion" it does have inode limits - based on a percentage of the filesystem size.

The source files could not be found.

I have several Windows 2012 VMs in a cloud environment and discovered I am unable to install certain roles / features. Attempting to do so fails with an "The source files could not be found." error. This somewhat misleading messages indicates Windows is looking for the OS install media. Most of the solutions on the Interwebz for working around this error describe how to set the server with an alternate path to the install media ...

Playing With Drive Images

I purchased a copy of Windows 10 on a USB thumbdrive. I chose to have media to have (a) a backup and (b) not to have to bother with downloading a massive image. Primarily this copy of Windows will be used in VirtualBox for testing, using Power Shell, and other tedious system administrivia. First thing when it arrived is I used dd to make a full image of thumbdrive so I could tuck it away in a safe place.

yum-config-manager --setopt=

It is common knowledge that on CentOS/RHEL hosts you can enable and disable defined reposities with the yum-config-manager. However it is also possible to use yum-config-manager tool to set any repository parameter using the setopt parameter.


dd is an underrated tool. What it lacks in user interface it makes up for with its swiss-army-knife number of purposes; from testing, to secure wiping, to backup and restore. But that user interface... it is bleak.

Ghostscript Font Testing

Viewing fonts on a screen and printing fonts to a printer are two different paths. Printing on LINUX almost always involves Postscript - of which PDF is a subtype - and the primary engine for creating or modifying Postscript is the Ghostscript package. Given the display path and the print path it is important to verify that a custom or third-party font is correctly installed and is working in Ghostscript.

Overrides With SSSD

LINUX has long been plagued with a rather lousy identity management scheme. Beyond the limitations of POSIX's getent and related calls [which can be very inefficient] the attempts to stub in network-aware identity services such as LDAP have only piled onto the rough edges. NSCD attempted to work around performance problems via caching - and did not do very well. Then was NSLCD the next evolution of NSCD which was better, but still inflexible. Identity management in more complex networks is a tedious business and what administrators need more than anything else is flexibility.

Testing A WINS Server

On a CIFS/SMB domain the WINS service is critical for proper function [some things use WINS, some things use DNS, it is terribly confusing, but it is what it is]. DNS is relatively easy to test and you will likely know right away if it isn't working. But before adding those new DCs to your dhcpd.conf file -

option netbios-name-servers,,;

... it would be nice to be equally confident WINS is operating as expected.


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