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Consulting On Cloud Nine

Perl: random order list howto

First Perl recipe here, to our best knowledge. The idea is very simple and obvious: using random function rand for randomly ordering values inside a sort pipeline. It could be used for any Perl lists or arrays random ordering, though we decided to sort hash array keys (as we tend to use that a lot in a form of hash array references).

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Amazon EC2 Windows instance with custom MAC on network interface

We were not able to alter MAC address of main network adapter inside a Windows 2012 R2 instance. No matter how we tried with registry hacks and even 3rd party software tools, the outcome was unsuccessful. Though for certain applications dependent on a particular MAC value it does not have to be on a primary network card. We realized we just needed another network card! That could be achieved by installing a dummy loopback network driver that would serve as an additional network interface. It can be assigned with a bogus IP while its physical (or MAC) address we may alter freely. Luckily, Microsoft offers such driver among most of its Windows distributions that is called KM-TEST Loopback Adapter.

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Amazon AWS automated snapshot copy to another region

In our initial post on the AWS topic we explained how to automate regular EBS volume snapshot creation using a small Linux instance as a controlling and automation server. Now it is time to fill in the gap of what happens next: automated copy from region 1 to region 2.

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Pressing oneself into Linux grub2 rescue shell

Reports surfaced recently that bypassing authentication of a Linux system equipped with Grub2 versions from 1.98 (December, 2009) to 2.02 (December, 2015) is as easy as pressing backspace key 28 times when the boot loader prompts for a username.

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Amazon AWS EC2 instance automatic shutdown by idle CPU

Amazon AWS instance may become very expensive when running 24/7. Our solution? An automatic shutdown when there is no need to have that server online. This recipe is simple when implemented with AWS’s functionality added not so long ago which was called CloudWatch monitoring.

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Amazon AWS instance volume backup: automate rolling snapshots and purge schedule

We begin a series of posts on our first-hand experience with Amazon Web Services (AWS) hosting platform and accompanied technologies. While allegedly possessing ten times more cloud resources than the top 14 other IaaS providers taken together (according to May 2015 reports), Amazon today is that certain behemoth reigning over them all. Economics aside, what amazes us most about AWS is how tons of feature-rich offerings, abundance of documentation, and gazillions of online discussions present so little for a young pioneer that takes on her first AWS quest. That is easy with AWS to launch an instance, though most of subsequent steps require planning, in some cases profound research, or, in other words, a difficult path full of trials, tribulations, and overdrawn accounts. That pay as you go paradigm needs budgeting and verification to be efficient.

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Printing via parallel port LPT interface on virtual Windows XP under Hyper-V

The main benefit of Windows XP mode on Windows 7 (virtual Windows XP instance under Hyper-V) would be to run legacy DOS applications or other older software that may not be compatible with newer versions of Windows. Also, some of those beasts would not know any better than to print directly to a hardware parallel printer port or LPT. For example, one of that legacy software is FoxPro. The LPT requirement presents a clear challenge since Microsoft did not provide an interface or driver for virtual Windows XP instance to access the host’s printer ports.

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